HESI A2 2026 Premium Review - Long Format Questions - Chemistry,
Biology, Anatomy, Math with Rationales - Guaranteed Pass
*Q1. CHEMISTRY - Reaction Kinetics*
Decomposition 2H2O2 → 2H2O + O2 catalyzed by iodide. Initial rate 0.02 M/s at
=0.1M. When doubled to 0.2M, rate becomes 0.08 M/s. Temp raised 25°C to 45°C +
platinum catalyst added. What is the order and effect?[H2O2]
A) First order, rate doubles, catalyst increases activation energy
B) Zero order, rate unchanged, catalyst has no effect
C) Second order, rate quadruples when concentration doubles, catalyst lowers activation energy
D) Third order, rate octuples, catalyst increases activation energy
*Answer: C*
*Q2. CHEMISTRY - Blood Buffer pH*
Blood pH 7.30 (normal 7.35-7.45). Henderson-Hasselbalch pH=pKa+log([HCO3-]/[H2CO3]),
pKa=6.1. Lab: [HCO3-]=22 mM, =1.4 mM. Patient hyperventilating. Diagnosis?[H2CO3]
A) Respiratory alkalosis, no effect
B) Metabolic acidosis, hyperventilation exhales CO2, shifts equilibrium to raise pH
C) Metabolic alkalosis, hyperventilation lowers pH
, D) Normal pH
*Answer: B*
*Q3. CHEMISTRY - IV Fluid Molarity*
Prepare 500 mL of 0.9% NaCl. 0.9% w/v =0.9g per 100mL. NaCl molar mass 58.5
g/mol, dissociates into 2 particles. Blood osmolarity ∼300 mOsm. Grams needed
and RBCs in 0.45% NaCl?
A) 9g, 0.3M, no effect on RBCs
B) 0.9g, 0.015M, hypotonic causes shrink
C) 4.5g, 0.154M, ∼308 mOsm isotonic, hypotonic 0.45% causes RBCs to swell and
lyse
D) 45g, 1.54M, RBCs shrink in hypotonic
*Answer: C*
*Q4. CHEMISTRY - Thermodynamics*
CaCO3(s) → CaO(s) + CO2(g) ΔH=+178 kJ/mol heated at 800°C. Student grinds
CaCO3 to powder. Correct?
A) Reaction exothermic, temperature no effect
B) Reaction endothermic, increasing temperature shifts to products, grinding increases rate by
surface area but does not change Keq
C) Grinding decreases rate
D) Endothermic and grinding changes Keq
*Answer: B*
*Q5. CHEMISTRY - Equilibrium*
N2O4 ⇌ 2NO2, N2O4 colorless, NO2 brown, Keq=0.36. More N2O4 added. What
happens?
A) Shifts to reactants, brown fades
B) No shift, Keq changes
C) Shifts to products, Keq increases
D) Shifts to products, brown intensifies, Keq unchanged unless temperature changes
*Answer: D*
*Q6. BIOLOGY - Blood Type Genetics*
Mother A genotype AO, father B genotype BO. Possible children blood types? Which universal
donor?
A) Only AB possible
B) Only O possible
C) Children AB,A,B,O; O possible because both carry recessive O; O- universal donor lacks
A,B,Rh antigens
Biology, Anatomy, Math with Rationales - Guaranteed Pass
*Q1. CHEMISTRY - Reaction Kinetics*
Decomposition 2H2O2 → 2H2O + O2 catalyzed by iodide. Initial rate 0.02 M/s at
=0.1M. When doubled to 0.2M, rate becomes 0.08 M/s. Temp raised 25°C to 45°C +
platinum catalyst added. What is the order and effect?[H2O2]
A) First order, rate doubles, catalyst increases activation energy
B) Zero order, rate unchanged, catalyst has no effect
C) Second order, rate quadruples when concentration doubles, catalyst lowers activation energy
D) Third order, rate octuples, catalyst increases activation energy
*Answer: C*
*Q2. CHEMISTRY - Blood Buffer pH*
Blood pH 7.30 (normal 7.35-7.45). Henderson-Hasselbalch pH=pKa+log([HCO3-]/[H2CO3]),
pKa=6.1. Lab: [HCO3-]=22 mM, =1.4 mM. Patient hyperventilating. Diagnosis?[H2CO3]
A) Respiratory alkalosis, no effect
B) Metabolic acidosis, hyperventilation exhales CO2, shifts equilibrium to raise pH
C) Metabolic alkalosis, hyperventilation lowers pH
, D) Normal pH
*Answer: B*
*Q3. CHEMISTRY - IV Fluid Molarity*
Prepare 500 mL of 0.9% NaCl. 0.9% w/v =0.9g per 100mL. NaCl molar mass 58.5
g/mol, dissociates into 2 particles. Blood osmolarity ∼300 mOsm. Grams needed
and RBCs in 0.45% NaCl?
A) 9g, 0.3M, no effect on RBCs
B) 0.9g, 0.015M, hypotonic causes shrink
C) 4.5g, 0.154M, ∼308 mOsm isotonic, hypotonic 0.45% causes RBCs to swell and
lyse
D) 45g, 1.54M, RBCs shrink in hypotonic
*Answer: C*
*Q4. CHEMISTRY - Thermodynamics*
CaCO3(s) → CaO(s) + CO2(g) ΔH=+178 kJ/mol heated at 800°C. Student grinds
CaCO3 to powder. Correct?
A) Reaction exothermic, temperature no effect
B) Reaction endothermic, increasing temperature shifts to products, grinding increases rate by
surface area but does not change Keq
C) Grinding decreases rate
D) Endothermic and grinding changes Keq
*Answer: B*
*Q5. CHEMISTRY - Equilibrium*
N2O4 ⇌ 2NO2, N2O4 colorless, NO2 brown, Keq=0.36. More N2O4 added. What
happens?
A) Shifts to reactants, brown fades
B) No shift, Keq changes
C) Shifts to products, Keq increases
D) Shifts to products, brown intensifies, Keq unchanged unless temperature changes
*Answer: D*
*Q6. BIOLOGY - Blood Type Genetics*
Mother A genotype AO, father B genotype BO. Possible children blood types? Which universal
donor?
A) Only AB possible
B) Only O possible
C) Children AB,A,B,O; O possible because both carry recessive O; O- universal donor lacks
A,B,Rh antigens
