ATS Chemistry: End of Y10 Test Review

What is the law of conservation of mass?

• Mass is always gained in a chemical reaction
• Mass is always lots in a chemical reaction
• The mass of reactants must always be greater than the mass of products
• The mass of reactants must always equal the mass of the product/s

Correctly balance the equation:
Cu + O₂ --> CuO

• 2Cu + 2O₂ --> CuO
• 2Cu + O₂ --> 2CuO
• Cu + 2O₂ --> 2CuO
• 2Cu + O₂ --> CuO

The mass of copper oxide produced when 4g of copper was heated in air was 6.25g. What was the mass of oxygen that it reacted with?

• 4g
• 6.25g
• 0.25g
• 2.25g

Acid + Base --> ?

• Salt + Water
• Salt + Hydrogen
• Salt + Carbon dioxide
• Salt + Water + Carbon dioxide

Acid + Alkali --> ?

• Salt + Water
• Salt + Hydrogen
• Salt + Carbon dioxide
• Salt + Water + Carbon dioxide

Acid + Metal --> ?

• Salt + Water
• Salt + Hydrogen
• Salt + Carbon dioxide
• Salt + Water + Carbon dioxide

Acid + Carbonate --> ?

• Salt + Water
• Salt + Hydrogen
• Salt + Carbon dioxide
• Salt + Water + Carbon dioxide

A solution of copper sulphate was heated in a process to obtain pure, dry crystals. What happened to the concentration of copper sulphate as the solution was heated?

• increased
• decreased
• stayed the same

Why is water removed from a solution by heating?

• It evaporates
• It condenses
• It freezes

If 2g of magnesium was heated make 3.78g of magnesium oxide, what % of magnesium would be present in the product?

• 50%
• 2%
• 53%
• 5.3%