Answer: B. (CH₃)₃N

Explanation: (CH₃)₃N is a Lewis base due to its lone pair of electrons on nitrogen, while (CH₃)₃C+, BF₃, and AlBr₃ act as Lewis acids by accepting electron pairs.

Answer: C. has lost one electron

Explanation: The molecular ion is formed by the loss of one electron from the parent molecule, resulting in a radical cation. It is a key peak in mass spectrometry that represents the intact molecule.

Answer: B. Losartan

Explanation: Losartan, an angiotensin receptor blocker, may diminish the effect of captopril by interfering with the renin-angiotensin system. Their interaction can reduce the overall blood pressure–lowering effect when used together.

Answer: A. Protamine

Explanation: Protamine is the antidote for heparin overdose. It binds to heparin and neutralizes its anticoagulant effects, thereby reducing the risk of bleeding complications.

Answer: B. EGFR

Explanation: Cetuximab is a monoclonal antibody that targets the epidermal growth factor receptor (EGFR), thereby inhibiting cell proliferation and survival in certain cancers, particularly colorectal and head and neck cancers.

Answer: B. Stability

Explanation: Zeta potential measurement provides an indication of the electrostatic repulsion between particles in a colloidal dispersion. A high absolute zeta potential value suggests a stable formulation with low aggregation tendency.

Answer: B. Lyotropic

Explanation: Cholesteryl esters form lyotropic liquid crystals, where the liquid crystalline phase is induced by the concentration of the lipid in a solvent. Their mesophase behavior depends on temperature and concentration.

Answer: A. q = 0

Explanation: When a liquid completely wets a solid surface, the contact angle (q) approaches 0°. This indicates perfect wetting where the liquid spreads uniformly over the surface.

Answer: B. Tetanus toxin

Explanation: Tetanus toxin binds to inhibitory neurons in the central nervous system and blocks glycine release, leading to spastic paralysis. This mechanism underlies the clinical syndrome known as tetanus.

Answer: B. caprolactam

Explanation: Nylon 6 is produced by the ring-opening polymerization of caprolactam. This process yields a polyamide with excellent mechanical properties and chemical resistance.

Answer: C. Rotational

Explanation: Rotational energy changes are typically much smaller than vibrational or electronic transitions. In some cases, the change in rotational quantum number may be too small to be observed in standard spectroscopic techniques.

Answer: B. Gymnosperm

Explanation: Taxol is obtained from the bark of yew trees, which are gymnosperms. These plants produce the anticancer agent Taxol naturally, and its extraction has led to extensive research and synthesis methods.

Answer: B. lower

Explanation: Dumping refers to selling a product in a foreign market at a price lower than in the domestic market, which is considered unfair competition and is subject to trade remedies.

Answer: A. Entropy

Explanation: Colligative properties depend on the number of solute particles in solution and are driven by entropy changes. The increase in disorder caused by the dissolved particles lowers the freezing point.

Answer: C. Weak solute-solvent interactions

Explanation: Positive deviations from Raoult’s Law occur when solute-solvent interactions are weak compared to solute-solute and solvent-solvent interactions, leading to higher vapor pressures than predicted.

Answer: B. true

Explanation: True density, which is the density of the solid material excluding air, is always higher than bulk, tap, or granule densities that account for void spaces between particles.

Answer: C. 0.015

Explanation: The regulatory limit for ethanol content in oral OTC solutions for adults is typically around 1.5% to ensure safety while still allowing the formulation to remain effective and palatable.

Answer: D. Decomposition caused by temperature

Explanation: Accelerated stability studies use increased temperatures to predict long-term stability. This approach is based on the Arrhenius equation, which relates reaction rate to temperature.

Answer: B. First-order

Explanation: Many drug decomposition processes follow first-order kinetics, where the rate of decomposition is proportional to the concentration of the drug, leading to an exponential decrease over time.

Answer: A. Sucrose

Explanation: Sucrose is a non-reducing sugar because its anomeric carbons are involved in the glycosidic bond, preventing it from acting as a reducing agent, unlike mannose, lactose, and fructose.