Chemistry Chapter 1 - Part 1

What is the relative atomic mass of an element based on?

• Hydrogen-1

• Oxygen-16

• Carbon-12

• The average of all elements in a compound

Calculate the Mr of calcium hydroxide, Ca(OH)₂. Given Ar: Ca = 40, O = 16, H = 1

• 56

• 58

• 74

• 76

What is the molar volume of gas at room temperature and pressure (r.t.p)?

• 24.0 dm³

• 22.4 cm³

• 6.02 × 10²³

• 44.0 dm³

Which of the following is the common unit for concentration?

• g/mol

• mol/dm³

• mol/cm³

• dm³/mol

How many molecules are in 2 moles of H₂ gas?

• 6.02 × 10²³ molecules

• 2 molecules

• 2.408 × 10²⁴ molecules

• 1.204 × 10²⁴ molecules

What is the mole of NaCl in 4.0 g if its Mr is 58.5?

• 0.0583 mol

• 0.0684 mol

• 0.0731 mol

• 234 mol

A student dissolves 1.2 g of potassium hydroxide (KOH) in 100 cm³ of water. What is the concentration?

• 0.12 mol/dm³

• 0.214 mol/dm³

• 0.012 mol/dm³

• 2.14 mol/dm³

Which of the following is true about isotopes?

• Same protons, different neutrons

• Different protons, same neutrons

• Same electrons, different mass

• Same mass, different electrons

What is the molar mass of CO₂?

• 28

• 44

• 40

• 30

How many atoms are in 0.25 mol of glucose (C₆H₁₂O₆)?

• 4.52 × 10²³

• 3.61 × 10²⁴

• 2.26 × 10²⁴

• 1.51 × 10²³