Balancing equations | Combined science | Quizalize & Oak National Academy

Starter quiz

What elements are present in CaCO₃ and how many atoms are there of each?
- calcium (1) and cobalt (3)
- calcium (3), carbon (3) and oxygen (3)
- carbon (1), actinium (1) and oxygen (3)
- calcium (1), carbon (1) and oxygen (3) ✓
Match the substance names and symbol formulae.
- magnesium oxide
  
  ⇔
  
  MgO ✓
- aluminium iodide
  
  ⇔
  
  AlI₃ ✓
- copper carbonate
  
  ⇔
  
  CuCO₃ ✓
- sodium hydroxide
  
  ⇔
  
  NaOH ✓
- potassium sulfate
  
  ⇔
  
  K₂SO₄ ✓
- strontium chloride
  
  ⇔
  
  SrCl₂ ✓
Match the substance to the correct state symbol.
- water
  
  ⇔
  
  H₂O (l) ✓
- ice
  
  ⇔
  
  H₂O (s) ✓
- steam
  
  ⇔
  
  H₂O (g) ✓
- dissolved sodium chloride
  
  ⇔
  
  NaCl (aq) ✓
- mercury at room temperature
  
  ⇔
  
  Hg (l) ✓
- helium at room temperature
  
  ⇔
  
  He (g) ✓
The chemical formula for magnesium oxide is MgO. In a chemical symbol equation, how would you amend this to provide twice as many Mg and O particles?
- Mg₂O₂
- 2Mg₂O
- 2MgO ✓
When 12.2 g of iron reacted with an unknown mass of sulfur, 20.6 g of a product was formed. What was the mass of the sulfur?
- 8.4 g ✓
- 32.8 g
- 12.2 g
- 6.1 g
- 10.3 g
Which symbol equation is correct for when bromine displaces iodine from sodium iodide solution?
- Br (l) + NaI (aq) → NaBr (aq) + I (l)
- Br₂ (g) + 2NaI (aq) → 2NaBr (aq) + I₂ (g)
- Br₂ (aq) + 2NaI (aq) → 2NaBr (aq) + I₂ (aq) ✓
- Br₂ (l) + NaI (aq) → NaBr (aq) + I₂ (l)