Question

How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2.0 M \( \text{HNO}_3 \)? The concentrated acid is 70% \( \text{HNO}_3 \).

• A. 90.0 g conc. \( \text{HNO}_3 \)
• B. 70.0 g conc. \( \text{HNO}_3 \)
• C. 54.0 g conc. \( \text{HNO}_3 \)
• D. 45.0 g conc. \( \text{HNO}_3 \)

Hint:

To prepare a diluted solution from a concentrated one, use the dilution equation \( C_1 V_1 = C_2 V_2 \).

Answer 1

The Correct Option is D

Step 1: Use the dilution equation.
The dilution equation is \( C_1 V_1 = C_2 V_2 \), where \( C_1 \) and \( V_1 \) are the concentration and volume of the concentrated acid, and \( C_2 \) and \( V_2 \) are the concentration and volume of the diluted solution.
Step 2: Calculate the amount of concentrated acid.
The volume of the concentrated acid required is calculated as follows: \[ \text{Mass of conc. acid} = \frac{C_2 V_2}{\text{percentage concentration}} \times 100 \] \[ \boxed{45.0 \, \text{g}} \]