Question

Concentrated nitric acid is labelled as 75%by mass. The volume in mL of the solution which contains 30 g of nitric acid is: Given: Density of nitric acid solution is 1.25 g/mL.

• A. 55
• B. 45
• C. 32
• D. 40

Hint:

When solving mass and volume problems, use the relationship \( {Density} = \frac{{Mass}}{{Volume}} \) to find the missing values.

Answer 1

The Correct Option is C

To determine the volume of a nitric acid solution containing 30 g of nitric acid, where the solution is 75% nitric acid by mass, follow these steps:

1. Determine the total mass of the solution needed. Given that the solution is 75% nitric acid by mass, the total mass (m_total) is calculated as:
   
   \( m_{\text{HNO}_3} = \frac{75}{100} \times m_{\text{total}} \)
   
   With \( m_{\text{HNO}_3} = 30 \) g:
   
   \( 30 = \frac{75}{100} \times m_{\text{total}} \)
   \( m_{\text{total}} = \frac{30 \times 100}{75} \)
   \( m_{\text{total}} = 40 \) g
2. Calculate the solution's volume using its density. The density (\( \rho \)) of the nitric acid solution is 1.25 g/mL. The formula is:
   
   \( \text{Volume (mL)} = \frac{\text{Mass (g)}}{\text{Density (g/mL)}} \)
   
   Substituting the values:
   
   \( \text{Volume} = \frac{40}{1.25} \)
   \( \text{Volume} = 32 \) mL

The required solution volume is 32 mL.