Question

Cu(s) + 4hno3(aq)= Cu(no3)(aq)+ 2No2(g) + 2h2O(l)

Answer 1

Answer:

29.0 g

Explanation:

We know that we will need a chemical equation with masses and molar masses, so let’s start by gathering all the information in one place.

$M_{r}$:      63.55                                              46.01

                    Cu + 4HNO₃ ⟶ Cu(NO₃)₂ + 2NO₂ + 2H₂O

Mass/g:    20.0

1. Use the molar mass of Cu to calculate the moles of Cu.

$\text{Moles of Cu} = \text{20.0 g Cu}\times \frac{\text{1 mol Cu} }{\text{63.55 g Cu}}= \text{0.3147 mol Cu}$

2. Use the molar ratio of NO₂:Cu to calculate the moles of NO₂.

$\text{Moles of NO}_{2} = \text{0.3147 mol Cu} \times \frac{\text{2 mol NO _{2} }}{\text{1 mol Cu}} = \text{0.6294 mol NO}_{2}$

3. Use the molar mass of NO₂ to calculate the mass of NO2.

$\text{Mass of NO}_{2} = \text{0.6294 mol NO _{2} }\times \frac{\text{46.01 g NO _{2} } }{\text{1 mol NO _{2} }}= \text{29.0 g NO}_{2}$