Question

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

How much No2 gas would be formed by the reaction of 20.0g of Cu?

Answer 1

29.0 g

Step-by-step 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}* \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} * \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$_(2)$}* \frac{\text{46.01 g NO$_(2)$} }{\text{1 mol NO$_(2)$}}= \text{29.0 g NO}_(2)`