Moles Practice Questions
Question 1
Q1. Knowledge Recall (1 mark)
Define the term 'mole'.
Question 2
Q2. Application of knowledge (2 marks)
Explain how the mass of a sample can be determined using the mole concept.
Question 3
Q3. Data Analysis/Calculations (3 marks)
A sample of sodium chloride has a mass of 2.5 g. Calculate the number of moles of sodium chloride present. (Relative atomic mass: Na = 23, Cl = 35.5)
Question 4
Q4. Knowledge Recall (2 marks)
State the formula for calculating the molar mass of a substance.
Question 5
Q5. Application of knowledge (3 marks)
A solution containing 1.5 mol of NaCl is diluted to a volume of 500 mL. Calculate the molarity of the new solution.
Question 6
Q6. Data Analysis/Calculations (4 marks)
A student needs to prepare 250 mL of a 0.2 M solution of sodium hydroxide. Calculate the mass of sodium hydroxide that is required. (Relative molecular mass: NaOH = 40)
Question 7
Q7. Knowledge Recall (1 mark)
Define the empirical formula of a compound.
Question 8
Q8. Application of knowledge (3 marks)
Explain how to determine the empirical formula of a compound from its percentage composition.
Question 9
Q9. Data Analysis/Calculations (3 marks)
A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. Calculate its empirical formula.
Question 10
Q10. Application of knowledge (3 marks)
Discuss the limitations of using the mole concept in the determination of atomic masses.