Most students walk into PCH 202 expecting to memorise reactions, then get blindsided by a single question: "distinguish between quality assurance and quality control." Miss that one distinction and a whole section of the paper unravels, because almost everything in this course hangs off the relationship QA = QC + GMP. That is the flavour of PCH 202. It rewards clean definitions and sharp contrasts far more than rote recall. This page is a student-written study companion for PCH 202 – Inorganic Pharmaceutical Chemistry, a core course for ABUAD 200 Level Pharmacy students in the second semester, College of Pharmacy.
The course sits on two legs. The first is the foundational chemistry a pharmacist actually uses: how electrons arrange themselves, why atoms bond the way they do, what functional groups do to a drug, and how to name organic compounds. The second is the applied heart of PCH 202, pharmaceutical assays and determination: how you prove a medicine is what the label says. The summaries below turn both halves of the syllabus into plain-English notes, with original practice questions and worked answers so you can check each idea has stuck. The complete study workbook sits in the interactive reader at the end as a free bonus to the notes on this page.
- Course: PCH 202 – Inorganic Pharmaceutical Chemistry
- College / Department: College of Pharmacy
- Level / Semester: 200 Level, Second Semester
- Topics covered: Atomic structure and quantum numbers, electronic configuration, periodic trends, bonding and hybridization, electronic effects, reaction mechanisms, functional groups, IUPAC nomenclature, pharmaceutically important elements, coordination and chelation, then the PCH 202 assays syllabus: QA/QC/GMP, assay types, errors and precision, physicochemical techniques, chromatography, immunoassay, bioassay, and purity
- Best for: Continuous assessment + final exam revision
Part One: Foundational Chemistry for PCH 202
1. Quantum Theory and the Four Quantum Numbers
Everything about how a drug behaves, whether it ionises, dissolves in water or fat, reacts or binds a receptor, traces back to how its electrons are arranged. Electrons are too small and fast for Newtonian physics, so their behaviour is described by a wavefunction, whose square gives the probability of finding an electron at a point. The key names to know are the Schrödinger equation (Hψ = Eψ) for lighter atoms, Dirac's equation for very heavy relativistic atoms, the Born-Oppenheimer approximation (freeze the slow nuclei, solve the fast electrons), and the Hartree-Fock self-consistent-field method for many-electron systems.
Solving these equations shows that energy, shape and orientation of orbitals are quantised, which gives rise to four quantum numbers. The principal (n) sets the shell and size, holding up to 2n² electrons. The azimuthal (l) runs 0 to (n-1) and fixes the subshell shape: s (spherical), p (dumbbell), d (cloverleaf), f (complex). The magnetic (ml) runs -l to +l, giving (2l+1) orientations. The spin (ms) is +½ or -½. The Pauli exclusion principle says no two electrons in one atom share all four. Exam tip: build a four-column table (name, symbol, what it determines, allowed values) and reproduce it from memory; that single table answers most opening questions on this topic.
2. Electronic Configuration of Elements
An element's configuration is how its electrons spread across shells, subshells and orbitals, written as shell-number, subshell-letter, superscript count, so oxygen is 1s² 2s² 2p⁴. Three rules govern the filling. The Aufbau principle fills the lowest-energy orbital first. The Pauli principle caps an orbital at two electrons of opposite spin. Hund's rule fills degenerate orbitals singly with parallel spins before any pairing begins.
Orbitals do not fill in plain numerical order because sub-levels overlap; the observed sequence starts 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p and so on. Watch the giveaway cases: calcium (Z=20) is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s², with 4s filling before 3d, and carbon's two 2p electrons sit in separate orbitals by Hund's rule. Valence electrons drive chemistry, which is why sodium, with one loosely held outer electron, is so reactive and so common in pharmacy salts. Exam tip: memorise the filling order as a chant and practise writing configurations for Z up to 20 by hand, since the 4s-before-3d switch is the trap examiners love.
3. The Periodic Table and Periodic Trends
The modern periodic law states that element properties are a periodic function of atomic number, not atomic mass. Elements sort into the s, p, d and f blocks, named after the subshell the valence electrons enter, with metals on the left and centre, non-metals upper right, and metalloids on the staircase between them.
Four trends carry most of the marks. Across a period (left to right) atomic radius decreases while ionisation energy, electron affinity and electronegativity increase; down a group the pattern reverses. The reason is the tug-of-war between more shells (down a group) and rising nuclear pull (across a period). Electronegativity is the one to prize, because the bigger the electronegativity gap between two bonded atoms, the more polar or ionic their bond becomes, which links atomic structure straight to bonding. Exam tip: learn the trends as a grid with two columns, across-a-period and down-a-group, and attach the one-line reason to each; questions almost always ask for the direction plus the why.
4. Chemical Bonding
Atoms bond because it lowers their energy, usually by reaching a full outer shell of eight (the octet rule, ns² np⁶). Which bond forms depends on electronegativity. A covalent bond shares one or more electron pairs between non-metals of similar electronegativity (H₂O, CH₄); such compounds have low melting points and poor conductivity. An ionic bond transfers electrons from a metal to a non-metal, creating attracting ions (NaCl, CaO); the lattice gives high melting points, water solubility and conductivity when molten or dissolved.
A coordinate (dative) bond is a covalent bond where both shared electrons come from one donor atom with a lone pair, given to an electron-deficient acceptor. The ammonium ion and carbon monoxide are the classic cases, and once formed a dative bond is indistinguishable from an ordinary covalent one. This bond type is the whole basis of the metal-ligand complexes covered later. Exam tip: keep a three-row table (bond type, electron behaviour, example pair) ready, and be able to say in one sentence why a coordinate bond is just a covalent bond with a one-sided electron source.
5. Orbitals and Hybridization
An orbital is the region around a nucleus where an electron is most likely to be found. When atoms bond, atomic orbitals overlap into molecular orbitals: a stabilising bonding orbital (σ, π) and a destabilising antibonding orbital (σ*, π*). The count of molecular orbitals equals the count of atomic orbitals combined, and the molecular-orbital picture explains why O₂ is paramagnetic (unpaired electrons in its π* orbitals), something a simple Lewis structure cannot.
Hybridization mixes atomic orbitals on one atom into new equal-energy orbitals that point where bonding needs them, explaining VSEPR shapes. Lock in the set: sp is linear at 180° (CO₂, ethyne), sp² is trigonal planar at 120° (BF₃, ethene), sp³ is tetrahedral at 109.5° (CH₄, NH₃, H₂O), sp³d is trigonal bipyramidal (PCl₅) and sp³d² is octahedral (SF₆). Exam tip: nitrogen in NH₃ and oxygen in H₂O are still sp³, but their lone pairs squeeze the bonds into pyramidal and bent shapes; expect a question that tests exactly that lone-pair effect.
6. Electronic Effects: Sigma, Pi, Polarity and Resonance
Four finer ideas control a molecule's strength and reactivity. A sigma bond is the strongest covalent bond, formed by head-on overlap, present in every single bond, and it allows free rotation. A pi bond is weaker, formed by sideways overlap of p-orbitals, appears only in double and triple bonds, and restricts rotation. So a C=C double bond is one sigma plus one pi, and a triple bond is one sigma plus two pi.
Bond polarity arises when bonded atoms differ in electronegativity, pulling electrons toward the stronger atom and creating δ+ and δ- partial charges; bonds range from non-polar covalent (O₂) through polar covalent (H₂O, HF) to fully ionic (NaCl). Polarity governs a drug's water solubility and hydrogen bonding. Resonance is electron delocalisation across a molecule when several valid Lewis structures can be drawn; the real molecule is a hybrid of them, which lowers energy, and benzene's six identical C-C bonds are the textbook proof. Exam tip: practise counting sigma and pi bonds in ethene and ethyne, and be ready to explain benzene's equal bond lengths using resonance in two clean sentences.
7. Bond Fission and Reaction Mechanisms
Reactions are just bonds making and breaking. In homolytic fission the bond splits evenly, each atom keeps one electron, and neutral free radicals form; it is favoured by non-polar bonds under UV light or heat (chlorine splitting to two chlorine radicals). In heterolytic fission the bond splits unevenly, one atom takes both electrons, and a cation and anion form; it is favoured by polar bonds and polar solvents (HCl ionising in water).
From there flow the main mechanisms: radical reactions via homolytic fission, nucleophilic substitution (SN1 and SN2) where a nucleophile replaces a leaving group, electrophilic addition to electron-rich double bonds, and elimination that creates a new double bond. Bond strength itself rises with shorter length and higher bond order, is equalised by resonance, and is tuned by inductive effects (electron-withdrawing groups weaken, donating groups strengthen). Exam tip: memorise the homolytic-versus-heterolytic contrast as a table (what splits, products, favoured by, typical setting); it is a frequent short-answer question, and quoting one example for each seals the mark.
8. Functional Groups and Drug Reactivity
A drug is a carbon skeleton decorated with functional groups, the reactive clusters that give a molecule its personality and control ionisation, solubility, stability, metabolism and receptor binding. They fall into four classes. Acidic groups donate H+ and impart water solubility (carboxylic acids, phenols, sulphonamides). Basic groups accept H+ (amines, guanidines, N-heterocycles). Neutral groups carry intermediate polarity and no net charge (alcohols, amides, esters, ethers, ketones). Lipophilic groups are non-polar and help a drug cross membranes (alkanes, aromatics, halides).
This acid-base character decides whether a medicine is sold as its free acid or base or as a more soluble salt, which is exactly why so many drugs appear as hydrochlorides and sodium salts. Keep a quick-reference of group, suffix and example handy: hydroxy/-ol for alcohols, -oic acid for carboxylic acids, -amine for amines, -one for ketones. Exam tip: do not just name the groups, sort a given drug's groups into acidic, basic, neutral or lipophilic and predict its solubility, because the applied version of this question is worth more than the list.
9. IUPAC Nomenclature of Organic Compounds
Nomenclature is the agreed rulebook so a pharmacist in Berlin and a chemist in New York mean the same molecule. Systematic IUPAC names follow one logic: prefix + parent + unsaturation + suffix. The four steps are: find the longest carbon chain that holds the highest-priority group, number from the end that gives that group the lowest locant, identify and number the substituents (using di-, tri- for repeats), then assemble the name as one word with substituents listed alphabetically.
Learn the roots (meth, eth, prop, but, pent, hex, hept, oct, non, dec) and the saturation suffixes: -ane for single bonds, -ene for C=C, -yne for triple bonds. The same rules name real medicines, which is what makes this examinable: ibuprofen is 2-(4-isobutylphenyl)propanoic acid, aspirin is 2-acetoxybenzoic acid, and paracetamol is N-(4-hydroxyphenyl)acetamide. Exam tip: practise naming a handful of branched chains and one aromatic derivative (toluene, phenol, aniline) by hand; getting the locant direction and alphabetical order right is where marks are usually lost.
10. Pharmaceutically Important Elements
Electronic configuration produces predictable group chemistry, and many of those elements matter in pharmacy as drugs, excipients or reagents. Group IA (alkali metals) are extremely reactive and never found free. Group IIA (alkaline earths) are reactive but less so, and their small, highly charged ions form complexes readily, as magnesium does in chlorophyll. Reactivity with water climbs down a group, from inert beryllium to calcium reacting with cold water.
The group-by-group pharmacy highlights are worth memorising with one example each: calcium for clotting, bone and antacids (calcium carbonate, gluconate); aluminium for slow antacids and suspending agents (aluminium hydroxide); iodine for antiseptics and thyroid disorders (iodine solution, KI); silver for topical antibacterials (silver nitrate); and manganese as an oxidising antibacterial (potassium permanganate). Exam tip: tie each element to one role and one official compound, and remember the octet rule plus periodic trends explain why the chemistry runs so predictably down each group.
11. Coordination Compounds and Chelation
A coordination compound forms when a central metal ion accepts lone pairs from surrounding molecules or ions through coordinate bonds. The vocabulary is the exam target. A ligand donates an electron pair (through N, O or a halogen). Denticity counts the donor atoms a ligand uses: monodentate (CN-), bidentate (oxalate) or polydentate (EDTA, which binds through four oxygens and two nitrogens). The coordination sphere is the metal plus its ligands in square brackets, and the coordination number is how many donor atoms attach. Naming lists ligands alphabetically, then the metal with its oxidation state in Roman numerals, so [Co(NH₃)₆]Cl₃ is hexaamminecobalt(III) chloride.
Chelation is coordination by a polydentate ligand that clamps the metal like a claw. When the complex is stable and water-soluble, the ligand acts as a sequestering agent, locking a metal away without removing it. This underpins real pharmacy: EDTA protects preparations from trace-metal discolouration and treats hypercalcaemia, citrate and oxalate act as in-vitro anticoagulants by sequestering calcium, and EDTA salts form an excretable chelate in lead poisoning. Exam tip: nail the four terms (ligand, denticity, coordination sphere, coordination number) with one example each, then give two named pharmaceutical uses of chelation, since that pairing is a common structured question.
Part Two: PCH 202 Pharmaceutical Assays and Determination
12. Drug Quality: QA, QC and GMP
A pharmacist is a custodian of therapeutic substances, responsible for guaranteeing that every product is fit for purpose. "Fit" is a multi-dimensional verdict covering chemical identity, purity, potency, stability, efficacy, safety and patient acceptability. Older practice judged quality by finished-article checks like appearance, hardness and average weight; modern practice treats those as necessary but far from sufficient and engineers quality into the whole manufacturing chain.
Three ideas structure this, and the relationship QA = QC + GMP ties them together. Quality Assurance is the wide umbrella, the whole system of standards and procedures guaranteeing quality from raw material to patient. Quality Control is a subset focused on testing and verification against specifications; it is reactive, catching problems after production. Good Manufacturing Practice governs the process itself (facility, equipment, staff, documentation, validation) and is proactive, preventing defects as they would occur. When quality fails, the cause usually traces to one of the 5Ms: Machines, Materials, Men, Method and Milieu. Exam tip: the QA-versus-QC-versus-GMP distinction is the single most-asked item; build a three-row table (nature, focus, reactive or proactive) and memorise the 5Ms as a list you can reproduce cold.
13. Assays: Definition, Types and Quality Criteria
An assay is an investigative procedure that both qualitatively confirms a target substance (the analyte) is present and quantitatively measures how much there is. It answers two questions at once: is it there, and how much. There are five assay families: chemical assays (chemical separation and quantification), bioassays (biological response in living tissue against a standard), microbiological assays (inhibition of microbial growth against a standard antibiotic), immunoassays (antigen-antibody binding read via a label), and physical assays (measuring a physical property).
Whatever the family, a dependable method shares five performance characteristics: sensitivity (reliably detecting a true positive, with a low detection cut-off), specificity (measuring the analyte cleanly despite impurities and degradants), repeatability (precision under the same conditions over a short time), validity (evidence the system does its job consistently) and stability-indicating power (tracking how quality changes with time). Exam tip: do not confuse sensitivity with specificity. Sensitivity is about catching what is truly present (few false negatives), specificity is about not being fooled by look-alikes; a one-line contrast of the two is a guaranteed easy mark.
14. Errors, Precision and Accuracy
Every result carries uncertainty, and three error types explain it. Gross errors are obvious breakdowns (a split sample, a wrong dilution, a broken instrument); you discard the result and restart. Systematic errors are a consistent one-directional bias from a flawed step, giving results that are precise but off-target. Random errors are unpredictable scatter in both directions, giving imprecise results whose mean may still land near the truth by luck.
The classic teaching example uses four students each assaying a 500 mg paracetamol tablet five times (100% = the stated content). Student 1 clusters tightly around 100% (precise and accurate). Student 2 clusters tightly but low (precise yet inaccurate, a systematic error). Student 3 scatters widely and low (imprecise and inaccurate, random error). Student 4 scatters widely yet averages near 100% (accurate mean by chance only). The mean is (Σxₕ)/N. Exam tip: memorise the one-line test, precision is how tightly repeats agree, accuracy is how close the mean sits to the true value, and be ready to label each of the four students and name the error at work.
15. Chemical Assays and Physicochemical Techniques
A chemical assay studies the separation, identification and quantification of a sample's components, splitting into qualitative work (which components are present, via extraction, distillation, precipitation) and quantitative work (how much is present, by volume or weight). Modern practice leans on physicochemical techniques that read a light signal to infer chemical quantity. The unifying idea is the Beer-Lambert law: absorbance is proportional to concentration and path length, with A = log(1/T), where T is transmittance.
The main techniques build on this. Flame photometry aspirates a sample into a flame that emits at element-characteristic wavelengths (sodium 589 nm yellow, lithium 670 nm red, calcium 622 nm orange). Colorimetry converts colourless compounds into coloured ones and reads fixed visible wavelengths, cheaply and portably. Spectrophotometry is the sensitive cousin, using a precisely selected wavelength over roughly 200 to 750 nm (UV and visible) through a quartz cuvette, and it can read colourless samples. Fluorimetry measures fluorescence emitted after excitation, with intensity proportional to concentration (used for adrenaline, riboflavin, morphine). Exam tip: be able to write A = log(1/T), state Beer-Lambert in one sentence, and give the colorimetry-versus-spectrophotometry contrast (fixed visible versus precisely selected UV-visible, coloured versus colourless samples).
16. Chromatography: Principles and Techniques
Chromatography, literally "to write with colour" after early plant-pigment separations, separates any mixture by exploiting the differential affinities of components for a stationary phase and a mobile phase; components partition differently, travel at different rates and separate. Learn the language: mobile phase (the moving solvent), stationary phase (the fixed adsorbent), eluent (fluid entering), eluate (fluid exiting), and affinity (interaction strength). The guiding rule is like-with-like: polar attracts polar, non-polar attracts non-polar.
Paper and thin-layer chromatography (TLC) are qualitative techniques read by the retardation factor, Rf = distance moved by solute / distance moved by solvent, a value between 0 and 1. Column, gas (GC) and high-performance liquid chromatography (HPLC) are read by retention time (Rt, which identifies a component) plus peak area against a calibration curve (which quantifies it). HPLC runs in normal phase (polar stationary, less polar mobile) or reverse phase (non-polar stationary, polar mobile), handles volatile and non-volatile compounds, and offers high resolution and reproducibility. Exam tip: keep the split crisp, paper and TLC give Rf and are qualitative, while GC and HPLC give Rt for identity and peak area for amount; a quantitative result is only valid when the sample falls inside the calibrated range.
17. Immunoassay
An immunoassay uses antibodies as reagents to detect or quantify an analyte through antigen-antibody binding, pairing exquisite specificity with very high sensitivity (often picogram-per-millilitre). The antibody grips a specific region (the epitope) of the target macromolecule (the antigen) at its own binding site (the paratope), driven by non-covalent forces. Because the binding itself is invisible, a label (enzyme, radioisotope, fluorescent dye, chemiluminescent compound or colloidal particle) converts it into a measurable signal read against a calibration curve.
Two format splits matter. In a competitive assay, sample analyte competes with a fixed amount of labelled tracer for limited antibody sites, so signal is inverse to concentration; it suits small single-epitope haptens (drugs, hormones). In a non-competitive (immunometric) assay, antibody is in excess and signal is directly proportional to analyte, giving better sensitivity for large multi-epitope proteins. The other split is operational: heterogeneous assays need a wash to separate bound from free label (ELISA, RIA), while homogeneous assays need no separation because binding itself changes the signal (EMIT, FPIA), making them fast and easy to automate. Exam tip: remember two contrasts, competitive gives an inverse signal for small analytes while non-competitive gives a direct signal for large ones, and heterogeneous needs washing while homogeneous does not.
18. Microbiological Assays and Bioassays
Some substances, especially antibiotics and certain hormones, are best measured by their biological effect. A microbiological assay compares the inhibition of microbial growth by a test antibiotic against known concentrations of a standard, by the cylinder-plate (cup-plate) method (measuring zones of inhibition on a seeded plate) or the turbidimetric method (measuring reduced turbidity in liquid culture). A bioassay compares the relative potency of a test compound against a standard on living tissue, in three types: direct, indirect graded (response rises with dose, as with acetylcholine on frog rectus muscle) and indirect quantal or all-or-none (such as insulin-induced convulsions in mice).
Bioassays are indicated when a chemical method is unavailable, too complex or too insensitive, when the active principle is unknown (insulin, pituitary extracts), or to compare potency across sources. They are less precise, more time-consuming and more sensitive than chemical assays. Accuracy within ±20% is good and within ±10% is excellent, and results depend on physiological salt solutions (Frog-Ringer, Kreb's, Tyrode, Ringer-Locke, De Jalon, McEwen) that keep the tissue alive, each matched to a tissue type. Exam tip: contrast bioassay with chemical assay in a table (precision, time, sensitivity, whether the structure is known), and remember the ±10% excellent, ±20% good accuracy limits.
19. Concentration Units and Determination of Purity
Quantitative assays rest on expressing concentration precisely. Molarity (M) is moles of solute per litre of solution; molality (m) is moles per kilogram of solvent; normality (N) is gram-equivalents per litre, equal to molarity times the equivalence factor (H₂SO₄ has n = 2). Note that molarity shifts slightly with temperature because volume expands, while molality is temperature-independent because it uses mass. Trace units follow: 1 ppm is 1 mg per litre, 1 ppb is 1 µg per litre.
Purity is judged by elemental analysis, comparing a sample's measured elemental composition against the theoretical composition of the pure compound. The workflow: write the formula, count atoms of each element, find each element's mass from the periodic table, sum for the molecular mass, then compute each element's mass-percent and compare with the measured values. For calcium chloride (CaCl₂), theory gives 36.11% Ca and 63.89% Cl, matching a measured 36.12% and 63.91% almost exactly, so the sample is pure. Exam tip: the molarity-versus-molality distinction (per litre of solution versus per kilogram of solvent, and why temperature matters) is a favourite short question, and you should be able to run one full purity calculation from formula to percentage by hand.
Sample Practice Questions (With Answers)
Here are a few representative questions, written in our own words, with the reasoning explained so you understand the why, not just the answer:
Q1. Distinguish between quality assurance, quality control and good manufacturing practice, and state the relationship between them.
Answer: QA is the whole umbrella system of standards and procedures that guarantees quality from raw material to patient. QC is a subset of QA that tests finished and in-process products against specifications; it is reactive, catching defects after production. GMP regulates the manufacturing process itself (facility, staff, documentation, validation) and is proactive, preventing defects as production happens. The relationship is QA = QC + GMP.
Q2. Four students each assay a 500 mg tablet five times. Student 2 gets tightly grouped results that all sit near 95% of the stated content. Classify the result and name the error.
Answer: The tight grouping means the work is precise, but a mean sitting well below the true 100% means it is inaccurate. Tight-but-displaced results point to a systematic error, a consistent one-directional bias from a single faulty step (perhaps a mis-calibrated instrument), rather than random scatter. Precision without accuracy is the signature of systematic error.
Q3. A colourless drug solution must be quantified at a precisely chosen wavelength in the UV region. Which technique fits, and why not a simple colorimeter?
Answer: Use spectrophotometry. A colorimeter reads only fixed wavelengths in the visible range and needs a coloured (or colour-developed) sample, so it cannot handle a colourless compound at a specific UV wavelength. Spectrophotometry covers roughly 200 to 750 nm, selects a precise wavelength through a monochromator and quartz cuvette, and reads colourless samples directly. Both still rest on the Beer-Lambert law, A = log(1/T).
Q4. In a competitive immunoassay the measured signal is high. Is the analyte concentration high or low, and why? Contrast with a non-competitive format.
Answer: The analyte concentration is low. In a competitive assay, sample analyte competes with a fixed amount of labelled tracer for limited antibody sites, so more analyte displaces more tracer and lowers the signal: signal is inverse to concentration. A non-competitive (immunometric) assay uses excess antibody, so signal is directly proportional to analyte and suits large multi-epitope proteins, while the competitive format suits small single-epitope haptens.
Q5. On a TLC plate a component moves 4.5 cm while the solvent front moves 9.0 cm. Find its Rf and say what the value tells you.
Answer: Rf = distance moved by solute / distance moved by solvent = 4.5 / 9.0 = 0.5. An Rf always lies between 0 and 1; this component travelled half as far as the solvent, so it has a moderate affinity for the stationary phase. Rf is a qualitative identifier: a component matching a known standard's Rf under identical conditions is likely the same substance. Paper and TLC are qualitative techniques.
Q6. Why is a coordinate bond described as a covalent bond, and how does chelation put it to pharmaceutical use?
Answer: A coordinate (dative) bond shares a pair of electrons like any covalent bond; the only difference is that both electrons come from one donor atom with a lone pair, given to an electron-deficient acceptor. Once formed it is indistinguishable in strength from an ordinary covalent bond. Chelation uses many such bonds at once: a polydentate ligand like EDTA clamps a metal through several donor atoms, forming a stable, water-soluble complex. This is used to sequester trace metals in preparations, to act as an in-vitro anticoagulant, and to form an excretable chelate in lead poisoning.
Q7. A CaCl₂ sample measures 36.12% calcium and 63.91% chlorine. Using Ca = 40.08 and Cl = 35.45, show whether it is pure.
Answer: Molecular mass = 40.08 + (2 × 35.45) = 110.98. %Ca = (40.08 / 110.98) × 100 = 36.11%, and %Cl = (70.90 / 110.98) × 100 = 63.89%. The theoretical values (36.11% Ca, 63.89% Cl) match the measured values (36.12%, 63.91%) almost exactly, so the sample is pure. Elemental analysis judges purity by comparing measured composition against the theoretical composition of the pure compound.
How to Study PCH 202 Effectively
- Master the definitions and contrasts first, because PCH 202 is examined on distinctions: QA versus QC versus GMP, precision versus accuracy, sensitivity versus specificity, competitive versus non-competitive, homogeneous versus heterogeneous. Learn each as a paired table, not a single term.
- Turn every comparison into a small table you can reproduce from memory (the three bond types, the hybridization shapes, the five assay families, the chromatography read-outs, the physiological salt solutions). Tables are how this course is actually tested.
- Practise the calculations by hand: mean of a data set, Rf and Rt interpretation, mass-percent purity, and molarity versus molality. Do not just read the worked examples, redo them cold.
- Anchor the foundational chemistry to pharmacy, because the "pharmaceutical relevance" angle is where marks hide: why sodium is reactive, why drugs are sold as salts, why oxygen is paramagnetic, why EDTA chelates.
- Memorise the short lists as complete sets with one example each: the 5Ms, the four quantum numbers, the four functional-group classes, the three error types, the six named salt solutions.
- Understand the summaries here first, then read the full workbook in the reader below and attempt the practice questions from memory before your exam.
Download the Full PCH 202 Practice Workbook
The notes above already cover both halves of the syllabus, but if you want everything in one place, the full PCH 202 – Inorganic Pharmaceutical Chemistry workbook is loaded in the reader just below: side-by-side comparison tables, worked assay calculations, the complete functional-group and coordination-naming references, and the physiological salt-solution chart. Flip through it right here on the page, or save a copy so you can keep drilling the QA/QC/GMP contrasts, the chromatography read-outs and the purity calculations offline in the days before your paper.
Frequently Asked Questions
Is this PCH 202 material free?
It is. There is no paywall, sign-up or fee here; the PCH 202 notes, practice questions and downloadable workbook are all open to any student who needs them.
Do I need a strong chemistry background to follow this?
You need the basics from first year, but the notes rebuild the foundations from atoms and bonding upward before reaching the assay techniques, so a shaky start is not fatal. Read Part One first to get the chemistry solid, then move into the Part Two assays material once functional groups and bonding feel comfortable.
Will these exact questions appear in my exam?
They will not. Everything in the practice set was written from scratch for revision, so use it to rehearse the reasoning and phrasing, not as a forecast of the questions your lecturer will actually set.
What is the fastest way to revise PCH 202 before the paper?
Start with the definitions and the paired contrasts (QA/QC/GMP, precision/accuracy, sensitivity/specificity), rebuild the key comparison tables from memory, then redo the calculations for the mean, Rf, and elemental purity by hand. Finish by attempting the practice questions without looking and reading the full workbook in the reader below.
About this resource: All summaries, explanations, study tips, and practice questions on this page were written, paraphrased, and adapted by the EverythingABUAD student team to support exam revision. This is an original study aid, not an official ABUAD document, and it is not a prediction of any future exam. Always cross-check with your lecturer's current course outline.
