Question

what is the volume of 15.8 M nitric acid is needed to ensure 1.00 g sample copper completely reacts

Answer 1

M(Cu) = 63.54 g/mol

n(Cu) $= \frac{1.00}{63.54} = 0.0157 \;mol$

According to the reaction equation:

n(HNO₃) = 4n(Cu) $= 4 \times 0.0157 = 0.0629 \;mol$

Proportion:

15.8 mol – 1000 mL

0.0629 mol – x

$x = \frac{0.0629 \times 1000}{15.8} = 3.98 \; mL ≈ 4 \;mL$

Answer: 4 mL