Calculations Involving Masses (Edexcel GCSE Chemistry: Combined Science)

Higher Only

What is the mass of 0.25 moles of hydrated copper(II) sulfate, CuSO₄.5H₂O?

Relative formula mass (M_r):  H₂O = 18  CuSO₄ = 160

	☐	A	40.0 g
	☐	B	44.5 g
	☐	C	62.5 g
	☐	D	1000 g

Higher Only

Nitrogen and hydrogen react together to make ammonia.

N₂ + 3H₂  → 2NH₃

If 2.0 g of hydrogen is added to 12.0 g of nitrogen which substance is the limiting reactant and how much of the excess reactant remains?

Relative atomic masses (A_r): H = 1    N = 14

			Limiting Reactant	Mass of excess reactant
	☐	A	nitrogen	2.0 g
	☐	B	nitrogen	10.0 g
	☐	C	hydrogen	2.7 g
	☐	D	hydrogen	9.3 g

A solution of CuSO₄ has a concentration of 35 g dm^-3.

What mass of CuSO₄ would there be in 250 cm³ of the solution?

	☐	A	140 g
	☐	B	8.75 g
	☐	C	7.14 g
	☐	D	1.40 g

What is the relative formula mass of butene, C₄H₈ ?

(relative atomic masses: H=1, C=12)

	☐	A	12
	☐	B	13
	☐	C	56
	☐	D	100