🧪 BIOCHEMISTRY CALCULATIONS QUESTIONS
Q1
Calculate the molarity of a solution prepared by dissolving 5.85 g of NaCl
(58.5 g/mol) in 500 mL of solution.
Q2
How many grams of glucose (180 g/mol) are required to prepare 250 mL
of a 0.5 M solution?
Q3
A solution contains 2 moles of solute in 2 L. Determine its molarity.
Q4
Calculate the molarity of a solution prepared by dissolving 15 g of urea (60
g/mol) in 300 mL of solution.
Q5
How many moles of solute are present in 2 L of a 0.75 M solution?
Q6
How much of a 2 M stock solution is required to prepare 100 mL of a 0.5
M solution?
,Q7
A 5 M solution is diluted to 1 M. If the final volume is 200 mL, calculate
the volume of stock solution required.
Q8
A solution has a hydrogen ion concentration of 1 × 10⁻³ M. Calculate its pH.
Q9
Calculate the molarity of a solution prepared by dissolving 14.6 g of NaCl
(58.5 g/mol) in 250 mL of solution.
Q10
How many grams of glucose (180 g/mol) are required to prepare 300 mL
of a 0.25 M solution?
Q11
A solution has a concentration of 2.5 M. What volume (in mL) is required to
contain 0.75 moles of solute?
Q12
Calculate the pH of a solution with hydrogen ion concentration [H⁺] = 4.0 ×
10⁻⁵ M.
Q13
Determine the hydrogen ion concentration [H⁺] of a solution with pH = 3.2.
Q14
A buffer solution has pKa = 6.0 and a ratio of [A⁻]/[HA] = 4. Calculate the
pH.
,Q15
Calculate ΔG at 298 K for a reaction with:
ΔH = −35 kJ/mol, ΔS = −0.080 kJ/mol·K
Q16
A biochemical reaction has ΔG° = −12 kJ/mol at 298 K. Calculate the
equilibrium constant K.
Q17
A student prepares a solution by dissolving 12 g of NaOH (40 g/mol) in
enough water to make 150 mL of solution. The solution is later diluted to
600 mL. Calculate the final molarity.
Q18
You mix 100 mL of 0.2 M HCl with 100 mL of 0.1 M NaOH. Assuming
complete neutralization, calculate the final pH of the solution.
Q19
A buffer is prepared using 0.3 M acetic acid (pKa = 4.76) and 0.15 M
sodium acetate. Calculate the pH of the buffer.
Q20
After adding 0.01 moles of HCl to 1 L of the buffer in Q19, calculate the
new pH.
Q21
A solution contains 0.02 M weak acid (HA) with Ka = 1.0 × 10⁻⁵.
Calculate the pH of the solution.
, Q22
Calculate the pH of a solution formed by mixing 50 mL of 0.1 M HCl with
150 mL of water.
Q23
A reaction has ΔH = +25 kJ/mol and ΔS = +0.10 kJ/mol·K.
Determine whether the reaction is spontaneous at 298 K, and calculate
ΔG.
Q24
At what temperature (K) will the reaction in Q23 become spontaneous?
Q25
A biochemical reaction has K = 0.01 at 298 K. Calculate ΔG° (R = 0.008314
kJ/mol·K).
Q26
A solution has pH = 8.5. Calculate:
a) [H⁺]
b) [OH⁻]
Q27
Calculate the pH of a buffer solution where [A⁻] = 0.25 M, [HA] = 0.05 M,
and pKa = 7.2.
Q28
A lab technician accidentally adds water to a buffer, doubling its volume.
Explain quantitatively how this affects the pH of the buffer (assume no
reaction occurs).
Q1
Calculate the molarity of a solution prepared by dissolving 5.85 g of NaCl
(58.5 g/mol) in 500 mL of solution.
Q2
How many grams of glucose (180 g/mol) are required to prepare 250 mL
of a 0.5 M solution?
Q3
A solution contains 2 moles of solute in 2 L. Determine its molarity.
Q4
Calculate the molarity of a solution prepared by dissolving 15 g of urea (60
g/mol) in 300 mL of solution.
Q5
How many moles of solute are present in 2 L of a 0.75 M solution?
Q6
How much of a 2 M stock solution is required to prepare 100 mL of a 0.5
M solution?
,Q7
A 5 M solution is diluted to 1 M. If the final volume is 200 mL, calculate
the volume of stock solution required.
Q8
A solution has a hydrogen ion concentration of 1 × 10⁻³ M. Calculate its pH.
Q9
Calculate the molarity of a solution prepared by dissolving 14.6 g of NaCl
(58.5 g/mol) in 250 mL of solution.
Q10
How many grams of glucose (180 g/mol) are required to prepare 300 mL
of a 0.25 M solution?
Q11
A solution has a concentration of 2.5 M. What volume (in mL) is required to
contain 0.75 moles of solute?
Q12
Calculate the pH of a solution with hydrogen ion concentration [H⁺] = 4.0 ×
10⁻⁵ M.
Q13
Determine the hydrogen ion concentration [H⁺] of a solution with pH = 3.2.
Q14
A buffer solution has pKa = 6.0 and a ratio of [A⁻]/[HA] = 4. Calculate the
pH.
,Q15
Calculate ΔG at 298 K for a reaction with:
ΔH = −35 kJ/mol, ΔS = −0.080 kJ/mol·K
Q16
A biochemical reaction has ΔG° = −12 kJ/mol at 298 K. Calculate the
equilibrium constant K.
Q17
A student prepares a solution by dissolving 12 g of NaOH (40 g/mol) in
enough water to make 150 mL of solution. The solution is later diluted to
600 mL. Calculate the final molarity.
Q18
You mix 100 mL of 0.2 M HCl with 100 mL of 0.1 M NaOH. Assuming
complete neutralization, calculate the final pH of the solution.
Q19
A buffer is prepared using 0.3 M acetic acid (pKa = 4.76) and 0.15 M
sodium acetate. Calculate the pH of the buffer.
Q20
After adding 0.01 moles of HCl to 1 L of the buffer in Q19, calculate the
new pH.
Q21
A solution contains 0.02 M weak acid (HA) with Ka = 1.0 × 10⁻⁵.
Calculate the pH of the solution.
, Q22
Calculate the pH of a solution formed by mixing 50 mL of 0.1 M HCl with
150 mL of water.
Q23
A reaction has ΔH = +25 kJ/mol and ΔS = +0.10 kJ/mol·K.
Determine whether the reaction is spontaneous at 298 K, and calculate
ΔG.
Q24
At what temperature (K) will the reaction in Q23 become spontaneous?
Q25
A biochemical reaction has K = 0.01 at 298 K. Calculate ΔG° (R = 0.008314
kJ/mol·K).
Q26
A solution has pH = 8.5. Calculate:
a) [H⁺]
b) [OH⁻]
Q27
Calculate the pH of a buffer solution where [A⁻] = 0.25 M, [HA] = 0.05 M,
and pKa = 7.2.
Q28
A lab technician accidentally adds water to a buffer, doubling its volume.
Explain quantitatively how this affects the pH of the buffer (assume no
reaction occurs).
