WBJEE · Chemistry
Mole concept, solutions and stoichiometry
44 practice questions, each with the answer and an explanation.
Practise Mole concept, solutions and stoichiometry now
Random questions from this topic, one at a time. You see the answer and the explanation straight after each one.
All 44 questions
- How many carbon dioxide molecules are present in 5 mol of CO₂? (Avogadro constant = 6.02 × 10²³ per mol)
- What is the molar mass of HNO₃? (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40, Mn = 55, Fe = 56)
- How many moles are there in 29.25 g of NaCl? (molar mass 58.5 g/mol)
- What is the mass of 5 mol of MgO? (molar mass 40 g/mol)
- 6 dm³ of a gas at 200 K is brought to 150 K at constant pressure. What is the new volume?
- How many methane molecules are present in 5 mol of CH₄? (Avogadro constant = 6.02 × 10²³ per mol)
- For A + B ⇌ 2C, the equilibrium concentrations are [A] = 2 mol/dm³, [B] = 2 mol/dm³ and [C] = 6 mol/dm³. What is Kc?
- What is the mass of 0.25 mol of KOH? (molar mass 56 g/mol)
- A gas occupies 4 dm³ at 5 atm. What volume does it occupy at 10 atm and constant temperature?
- 10 dm³ of a gas at 400 K is brought to 300 K at constant pressure. What is the new volume?
- How many carbon dioxide molecules are present in 0.5 mol of CO₂? (Avogadro constant = 6.02 × 10²³ per mol)
- How many moles are there in 53 g of Na₂CO₃? (molar mass 106 g/mol)
- A gas occupies 4 dm³ at 4 atm. What volume does it occupy at 20 atm and constant temperature?
- How many carbon dioxide molecules are present in 0.25 mol of CO₂? (Avogadro constant = 6.02 × 10²³ per mol)
- A current of 9.65 A is passed for 1000 s through a solution of a zinc salt, where each Zn ion gains 2 electrons. What mass of zinc is deposited? (F = 96500 C/mol; molar mass 65 g/mol)
- How many moles are there in 31.5 g of HNO₃? (molar mass 63 g/mol)
- A gas occupies 2 dm³ at 5 atm. What volume does it occupy at 25 atm and constant temperature?
- A gas at 1 atm, 2 dm³ and 400 K changes to 8 atm and 300 K. What is the new volume?
- A current of 24.125 A is passed for 2000 s through a solution of a copper salt, where each Cu ion gains 2 electrons. What mass of copper is deposited? (F = 96500 C/mol; molar mass 63.5 g/mol)
- What is the molar mass of KOH? (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40, Mn = 55, Fe = 56)
- How many moles are there in 51 g of NH₃? (molar mass 17 g/mol)
- What is the mass of 1.5 mol of H₂SO₄? (molar mass 98 g/mol)
- How many oxygen molecules are present in 3 mol of O₂? (Avogadro constant = 6.02 × 10²³ per mol)
- What is the molar mass of CO₂? (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40, Mn = 55, Fe = 56)
- How many moles are there in 25 g of CaCO₃? (molar mass 100 g/mol)
- What is the mass of 5 mol of KOH? (molar mass 56 g/mol)
- A gas occupies 10 dm³ at 5 atm. What volume does it occupy at 25 atm and constant temperature?
- 4 dm³ of a gas at 400 K is brought to 600 K at constant pressure. What is the new volume?
- How many water molecules are present in 2 mol of H₂O? (Avogadro constant = 6.02 × 10²³ per mol)
- How many moles are there in 132 g of CO₂? (molar mass 44 g/mol)
- What is the mass of 3 mol of H₂O? (molar mass 18 g/mol)
- How many neutrons are in an atom of Cl-35 (atomic number 17)?
- 2 dm³ of a gas at 400 K is brought to 300 K at constant pressure. What is the new volume?
- A gas at 2 atm, 2 dm³ and 300 K changes to 8 atm and 600 K. What is the new volume?
- A first-order reaction has a rate constant of 0.0231 per min. What is its half-life? (ln 2 = 0.693)
- How many moles are there in 190 g of MgCl₂? (molar mass 95 g/mol)
- What is the mass of 0.5 mol of CaO? (molar mass 56 g/mol)
- A gas occupies 4 dm³ at 5 atm. What volume does it occupy at 20 atm and constant temperature?
- 4 dm³ of a gas at 400 K is brought to 300 K at constant pressure. What is the new volume?
- A gas at 4 atm, 2 dm³ and 400 K changes to 2 atm and 600 K. What is the new volume?
- A current of 19.3 A is passed for 1000 s through a solution of a zinc salt, where each Zn ion gains 2 electrons. What mass of zinc is deposited? (F = 96500 C/mol; molar mass 65 g/mol)
- What is the molar mass of C₆H₁₂O₆? (H = 1, C = 12, N = 14, O = 16, Na = 23, Mg = 24, Al = 27, S = 32, Cl = 35.5, K = 39, Ca = 40, Mn = 55, Fe = 56)
- What is the electronic configuration (shell by shell) of the element Be (atomic number 4)?
- A gas occupies 4 dm³ at 1 atm. What volume does it occupy at 2 atm and constant temperature?