Chemistry: Practice Question
Sheet
Q How many molecules are present in 5.6 L of CO₂ at STP?
Q Calculate the number of atoms in 4.6 g of Na.
Q Determine the empirical formula of a compound with 40% C, 6.67% H, and 53.33% O.
Q What mass of NaOH is needed to prepare 250 mL of 0.2 M solution?
Q Calculate the molarity of a solution containing 5.3 g Na₂CO₃ in 250 mL.
Q 4.9 g of H₂SO₄ is dissolved in water to make 1 L of solution. Find its normality.
Q 2 g of a gas occupies 1.12 L at STP. Calculate its molar mass.
Q Calculate the volume of 1 mole of gas at 300 K and 1 atm using ideal gas law.
Q 5.3 g of Na₂CO₃ is dissolved in 500 mL water. Calculate molality.
Q Calculate % composition of elements in C₆H₁₂O₆.
Q How many litres of O₂ are needed to burn 5 g of CH₄ completely?
Q Find number of moles of electrons in 9650 C.
Q Calculate the oxidation number of Cr in Cr₂O₇²⁻.
Q Find the equivalent weight of H₂SO₄ in a reaction forming NaHSO₄.
Q Determine oxidation number of Mn in KMnO₄.
Q A 0.01 M solution of a weak acid has pH = 4. Find Ka.
Q Calculate the pH of a 0.001 M HCl solution.
Q Calculate pH of 0.1 M CH₃COOH if Ka = 1.8 × 10⁻⁵.
Q Determine pOH and [H⁺] for a solution with pH = 3.
Q Calculate pH of a buffer formed by 0.1 M CH₃COOH and 0.1 M CH₃COONa.
Q Calculate solubility of AgCl if Ksp = 1.6 × 10⁻¹⁰.
Q Find molar solubility of BaSO₄ if Ksp = 1.1 × 10⁻¹⁰.
Q Determine the solubility of Ca(OH)₂ in water if Ksp = 6.5 × 10⁻⁶.
Q A solution of NaOH has pH = 13. Calculate its concentration.
Q Calculate EMF of a Daniell cell: Zn | Zn²⁺ (0.1 M) || Cu²⁺ (1 M) | Cu.
Q Find the EMF of a galvanic cell if standard EMF is 1.1 V and temperature is 298 K.
Q How many grams of Cu will be deposited from 2 F of charge?
Q How many moles of Al³⁺ are reduced by 289500 C?
Q Determine the cell potential at 298 K for Zn | Zn²⁺ (0.01 M) || Cu²⁺ (1 M) | Cu.
Q Find ΔG for a reaction if E° = 1.1 V and n = 2.
Q A 2 molal solution of urea is prepared using 500 g water. Calculate molality.
Q Calculate boiling point elevation for 0.5 molal NaCl (Kb = 0.52°C·mol⁻¹·kg⁻¹).
Q Find ΔTf for 1 molal solution of KCl in water (Kf = 1.86°C·mol⁻¹·kg⁻¹, i = 2).
Q Calculate molar mass from freezing point depression = 0.93°C.
Q Find the osmotic pressure of 0.1 M glucose solution at 300 K.
Q 0.1 mol of NaCl is dissolved in 500 mL water. Calculate relative lowering of vapour pressure.
Q Calculate mole fraction of solute if vapour pressure of solution is 95% that of pure solvent.
Q 4 g of non-electrolyte in 250 mL produces osmotic pressure of 3 atm at 300 K. Find molar
mass.
, Q Calculate ΔH for CH₄ + 2O₂ → CO₂ + 2H₂O using bond enthalpies.
Q Calculate ΔG if ΔH = –40 kJ/mol, ΔS = –100 J/mol·K at 298 K.
Q For a first order reaction with t½ = 10 min, find rate constant.
Q 75% of a 1st order reaction completes in 60 min. Calculate rate constant.
Q Determine the time taken for 90% completion of a first order reaction (k = 2.303/t ×
log(100/10)).
Q The rate of reaction doubles when T increases from 300 to 310 K. Find Ea.
Q Determine order of reaction if rate constant has unit L mol⁻¹ s⁻¹.
Q A reaction has rate = k[A][B]. What is overall order?
Q Calculate λ (wavelength) of electron accelerated through 100 V.
Q Energy of radiation is 3.0 × 10⁻¹⁹ J. Find its wavelength.
Q How many photons are in 2 J of light of 500 nm wavelength?
Q Find de Broglie wavelength of a 1 g particle moving at 10 m/s.
Q Calculate energy change when an electron jumps from n = 3 to n = 2 in hydrogen atom.
Q Radius of hydrogen atom in first orbit is 0.53 Å. Find its energy.
Q Calculate bond order of O₂ using MO theory.
Q Determine number of unpaired electrons in Ni²⁺.
Q Calculate formal charge on O in CO₃²⁻.
Q Calculate % ionic character of HCl using μ = 1.08 D and r = 1.27 Å.
Q Determine lattice energy using Born-Haber cycle.
Q A gas occupies 2 L at 300 K. Find its volume at 400 K at constant pressure.
Q Calculate pressure if 2 mol of gas occupies 5 L at 300 K.
Q A gas has density 1.25 g/L at STP. Find molar mass.
Q A solution contains 0.1 mol CH₃COOH and 0.1 mol NaOH. Find pH after reaction.
Q In a buffer, [acid] = 0.1 M, [salt] = 0.2 M, pKa = 4.75. Find pH.
Q 1 L of 0.1 M HCl is added to 1 L of 0.1 M NaOH. Find final pH.
Q Find pH of 0.01 M H₂SO₄.
Q 20 mL of 0.1 M HCl is mixed with 30 mL of 0.1 M NaOH. Find pH.
Q A solution has [OH⁻] = 10⁻³ M. Find its pH.
Q Calculate ΔTf for 0.1 molal solution of glucose (Kf = 1.86°C·mol⁻¹·kg⁻¹).
Q Calculate the amount of CO₂ formed from 1 mol of CaCO₃.
Q Find mass of Ag deposited by 96500 C of charge.
Q Balance the redox reaction: MnO₄⁻ + Fe²⁺ → Mn²⁺ + Fe³⁺ in acid medium.
Q Determine ΔE when 1 mol of electron is moved through 1 V.
Q Determine bond angle and geometry of CH₄.
Q How many π bonds are in benzene?
Q Determine hybridization of carbon in CH₃⁻.
Q A mixture contains 2 moles O₂ and 3 moles N₂. Find mole fraction of O₂.
Q Partial pressure of N₂ in a gas mixture is 600 mmHg. Total pressure is 1 atm. Find mole
fraction of N₂.
Q Determine degree of dissociation of N₂O₄ if 1 mol produces 1.8 mol total gases.
Q Kp = 0.04 atm at 600 K for N₂O₄ ⇌ 2NO₂. Find Kc.
Q Determine heat released when 0.1 mol HCl reacts with 0.1 mol NaOH (ΔH = –57.3 kJ/mol).
Q A reaction is spontaneous at all temperatures. What sign of ΔH and ΔS supports this?
Q What is pressure of 1 mol gas at 300 K in 5 L? Use ideal gas law.
Q Calculate pH of a 0.001 M H₂SO₄ solution considering full ionization.
Sheet
Q How many molecules are present in 5.6 L of CO₂ at STP?
Q Calculate the number of atoms in 4.6 g of Na.
Q Determine the empirical formula of a compound with 40% C, 6.67% H, and 53.33% O.
Q What mass of NaOH is needed to prepare 250 mL of 0.2 M solution?
Q Calculate the molarity of a solution containing 5.3 g Na₂CO₃ in 250 mL.
Q 4.9 g of H₂SO₄ is dissolved in water to make 1 L of solution. Find its normality.
Q 2 g of a gas occupies 1.12 L at STP. Calculate its molar mass.
Q Calculate the volume of 1 mole of gas at 300 K and 1 atm using ideal gas law.
Q 5.3 g of Na₂CO₃ is dissolved in 500 mL water. Calculate molality.
Q Calculate % composition of elements in C₆H₁₂O₆.
Q How many litres of O₂ are needed to burn 5 g of CH₄ completely?
Q Find number of moles of electrons in 9650 C.
Q Calculate the oxidation number of Cr in Cr₂O₇²⁻.
Q Find the equivalent weight of H₂SO₄ in a reaction forming NaHSO₄.
Q Determine oxidation number of Mn in KMnO₄.
Q A 0.01 M solution of a weak acid has pH = 4. Find Ka.
Q Calculate the pH of a 0.001 M HCl solution.
Q Calculate pH of 0.1 M CH₃COOH if Ka = 1.8 × 10⁻⁵.
Q Determine pOH and [H⁺] for a solution with pH = 3.
Q Calculate pH of a buffer formed by 0.1 M CH₃COOH and 0.1 M CH₃COONa.
Q Calculate solubility of AgCl if Ksp = 1.6 × 10⁻¹⁰.
Q Find molar solubility of BaSO₄ if Ksp = 1.1 × 10⁻¹⁰.
Q Determine the solubility of Ca(OH)₂ in water if Ksp = 6.5 × 10⁻⁶.
Q A solution of NaOH has pH = 13. Calculate its concentration.
Q Calculate EMF of a Daniell cell: Zn | Zn²⁺ (0.1 M) || Cu²⁺ (1 M) | Cu.
Q Find the EMF of a galvanic cell if standard EMF is 1.1 V and temperature is 298 K.
Q How many grams of Cu will be deposited from 2 F of charge?
Q How many moles of Al³⁺ are reduced by 289500 C?
Q Determine the cell potential at 298 K for Zn | Zn²⁺ (0.01 M) || Cu²⁺ (1 M) | Cu.
Q Find ΔG for a reaction if E° = 1.1 V and n = 2.
Q A 2 molal solution of urea is prepared using 500 g water. Calculate molality.
Q Calculate boiling point elevation for 0.5 molal NaCl (Kb = 0.52°C·mol⁻¹·kg⁻¹).
Q Find ΔTf for 1 molal solution of KCl in water (Kf = 1.86°C·mol⁻¹·kg⁻¹, i = 2).
Q Calculate molar mass from freezing point depression = 0.93°C.
Q Find the osmotic pressure of 0.1 M glucose solution at 300 K.
Q 0.1 mol of NaCl is dissolved in 500 mL water. Calculate relative lowering of vapour pressure.
Q Calculate mole fraction of solute if vapour pressure of solution is 95% that of pure solvent.
Q 4 g of non-electrolyte in 250 mL produces osmotic pressure of 3 atm at 300 K. Find molar
mass.
, Q Calculate ΔH for CH₄ + 2O₂ → CO₂ + 2H₂O using bond enthalpies.
Q Calculate ΔG if ΔH = –40 kJ/mol, ΔS = –100 J/mol·K at 298 K.
Q For a first order reaction with t½ = 10 min, find rate constant.
Q 75% of a 1st order reaction completes in 60 min. Calculate rate constant.
Q Determine the time taken for 90% completion of a first order reaction (k = 2.303/t ×
log(100/10)).
Q The rate of reaction doubles when T increases from 300 to 310 K. Find Ea.
Q Determine order of reaction if rate constant has unit L mol⁻¹ s⁻¹.
Q A reaction has rate = k[A][B]. What is overall order?
Q Calculate λ (wavelength) of electron accelerated through 100 V.
Q Energy of radiation is 3.0 × 10⁻¹⁹ J. Find its wavelength.
Q How many photons are in 2 J of light of 500 nm wavelength?
Q Find de Broglie wavelength of a 1 g particle moving at 10 m/s.
Q Calculate energy change when an electron jumps from n = 3 to n = 2 in hydrogen atom.
Q Radius of hydrogen atom in first orbit is 0.53 Å. Find its energy.
Q Calculate bond order of O₂ using MO theory.
Q Determine number of unpaired electrons in Ni²⁺.
Q Calculate formal charge on O in CO₃²⁻.
Q Calculate % ionic character of HCl using μ = 1.08 D and r = 1.27 Å.
Q Determine lattice energy using Born-Haber cycle.
Q A gas occupies 2 L at 300 K. Find its volume at 400 K at constant pressure.
Q Calculate pressure if 2 mol of gas occupies 5 L at 300 K.
Q A gas has density 1.25 g/L at STP. Find molar mass.
Q A solution contains 0.1 mol CH₃COOH and 0.1 mol NaOH. Find pH after reaction.
Q In a buffer, [acid] = 0.1 M, [salt] = 0.2 M, pKa = 4.75. Find pH.
Q 1 L of 0.1 M HCl is added to 1 L of 0.1 M NaOH. Find final pH.
Q Find pH of 0.01 M H₂SO₄.
Q 20 mL of 0.1 M HCl is mixed with 30 mL of 0.1 M NaOH. Find pH.
Q A solution has [OH⁻] = 10⁻³ M. Find its pH.
Q Calculate ΔTf for 0.1 molal solution of glucose (Kf = 1.86°C·mol⁻¹·kg⁻¹).
Q Calculate the amount of CO₂ formed from 1 mol of CaCO₃.
Q Find mass of Ag deposited by 96500 C of charge.
Q Balance the redox reaction: MnO₄⁻ + Fe²⁺ → Mn²⁺ + Fe³⁺ in acid medium.
Q Determine ΔE when 1 mol of electron is moved through 1 V.
Q Determine bond angle and geometry of CH₄.
Q How many π bonds are in benzene?
Q Determine hybridization of carbon in CH₃⁻.
Q A mixture contains 2 moles O₂ and 3 moles N₂. Find mole fraction of O₂.
Q Partial pressure of N₂ in a gas mixture is 600 mmHg. Total pressure is 1 atm. Find mole
fraction of N₂.
Q Determine degree of dissociation of N₂O₄ if 1 mol produces 1.8 mol total gases.
Q Kp = 0.04 atm at 600 K for N₂O₄ ⇌ 2NO₂. Find Kc.
Q Determine heat released when 0.1 mol HCl reacts with 0.1 mol NaOH (ΔH = –57.3 kJ/mol).
Q A reaction is spontaneous at all temperatures. What sign of ΔH and ΔS supports this?
Q What is pressure of 1 mol gas at 300 K in 5 L? Use ideal gas law.
Q Calculate pH of a 0.001 M H₂SO₄ solution considering full ionization.
