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🇵🇰 AKU MBBS Admission Test · flashcards
AKU MBBS Admission Test Chemistry Flashcards
67 question-and-answer cards covering Chemistry as it is examined in AKU MBBS Admission Test. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Chemistry deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
Does adding a catalyst shift the position of equilibrium?
No. A catalyst speeds up both forward and reverse reactions equally, so equilibrium is reached faster but the position and value of K are unchanged.
Define acids and bases according to the Brønsted-Lowry and Arrhenius theories.
Arrhenius: acid releases H+, base releases OH- in water. Brønsted-Lowry: acid is a proton (H+) donor, base is a proton acceptor.
Define pH and pOH, and state their relationship at 25°C.
pH = -log[H+]; pOH = -log[OH-]. At 25°C, pH + pOH = 14, and Kw = [H+][OH-] = 1×10^-14.
Calculate the pH of a 0.01 M HCl solution.
HCl is a strong acid, fully dissociated, so [H+] = 0.01 M = 1×10^-2 M. pH = -log(10^-2) = 2.
What is a buffer solution and what does it contain?
A buffer resists changes in pH on adding small amounts of acid or base. It contains a weak acid and its conjugate base (or a weak base and its conjugate acid).
Write the solubility product (Ksp) expression for a salt AxBy that dissolves as xA^+ + yB^-.
Ksp = [A^+]^x [B^-]^y, using the equilibrium concentrations of the ions in a saturated solution. Solids are not included.
How is the precipitation of a salt predicted using Ksp and the ionic product (Q)?
Compare Q (ionic product) with Ksp: if Q > Ksp a precipitate forms (supersaturated); Q = Ksp is saturated (equilibrium); Q < Ksp is unsaturated (no precipitate, more can dissolve).
What is the common ion effect?
The decrease in solubility of a slightly soluble salt when a soluble salt sharing a common ion is added; the added ion shifts the dissolution equilibrium backward (Le Chatelier).
Define enthalpy change (ΔH) and distinguish exothermic from endothermic reactions.
ΔH is the heat change at constant pressure. Exothermic: releases heat, ΔH negative. Endothermic: absorbs heat, ΔH positive.
State Hess's Law.
The total enthalpy change for a reaction is the same regardless of the route taken, depending only on initial and final states. So ΔH for an overall reaction equals the sum of ΔH of its steps.
Define standard enthalpy of formation (ΔHf°) and give its value for an element in its standard state.
The enthalpy change when one mole of a compound forms from its constituent elements in their standard states at 298 K and 1 atm. ΔHf° of any element in its standard state is zero.
How is ΔH°reaction calculated from standard enthalpies of formation?
ΔH°rxn = Σ ΔHf°(products) − Σ ΔHf°(reactants), each multiplied by its stoichiometric coefficient.
Define entropy (S) and state the sign of ΔS for melting and for gas formation.
Entropy is a measure of disorder/randomness in a system. ΔS is positive (increases) for melting (solid→liquid) and for forming gases or increasing gas moles.
Write the Gibbs free energy equation and the condition for spontaneity.
ΔG = ΔH − TΔS. A reaction is spontaneous when ΔG < 0, at equilibrium when ΔG = 0, and non-spontaneous when ΔG > 0.
Under what combinations of ΔH and ΔS signs is a reaction always or never spontaneous?
ΔH negative and ΔS positive: spontaneous at all temperatures. ΔH positive and ΔS negative: never spontaneous. The other two cases are temperature-dependent.
How is rate of reaction defined and what are its typical units?
Rate is the change in concentration of a reactant or product per unit time (Δ[concentration]/Δtime). Units: mol dm^-3 s^-1 (or M/s).
What is a rate law, and define the order of reaction.
Rate law: Rate = k[A]^m[B]^n, where k is the rate constant. The order with respect to a reactant is its exponent; overall order = sum of exponents (m + n).
What is the half-life of a first-order reaction and how does it depend on concentration?
For first order, t1/2 = 0.693/k. It is constant and independent of the initial concentration of reactant.
List the main factors that affect the rate of a chemical reaction.
Concentration (or pressure for gases), temperature, surface area of solids, presence of a catalyst, and the nature of reactants (and light for some reactions).
According to collision theory, what two conditions must colliding molecules satisfy to react?
They must collide with sufficient energy (≥ activation energy, Ea) and with the correct (proper) orientation.
Why does increasing temperature increase reaction rate?
Higher temperature increases the average kinetic energy, so a greater fraction of molecules have energy ≥ Ea and collisions are more frequent and more energetic, increasing the rate (roughly doubling per 10°C rise).
Define activation energy (Ea).
The minimum energy that colliding reactant molecules must possess to form the activated complex and convert into products.
What is a catalyst and how does it speed up a reaction?
A substance that increases reaction rate without being consumed, by providing an alternative reaction pathway with a lower activation energy. It does not change ΔH or the equilibrium position.
Differentiate homogeneous and heterogeneous catalysis with an example of each.
Homogeneous: catalyst in the same phase as reactants (e.g., H2SO4 in ester hydrolysis). Heterogeneous: catalyst in a different phase (e.g., solid iron in the Haber process with gaseous reactants).
What this deck covers
The Chemistry deck follows the AKU MBBS Admission Test Chemistry syllabus — 9 chapters and 28 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 7.4 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 146 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Chemistry flashcards FAQ
How many Chemistry flashcards are in this AKU MBBS Admission Test deck?
67 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these AKU MBBS Admission Test flashcards free?
Yes. The preview here is free to read with no signup, and the full 67-card deck is free inside the Examius app.
What do the Chemistry cards cover?
They follow the AKU MBBS Admission Test Chemistry syllabus — 9 chapters and 28 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.