Question

the hydrogen ion concentration of a solution prepared by diluting 50. mL of 0.10 M HNO3(aq) with water to 500. mL of solution is?

Answer 1

The hydrogen ion concentration of a solution prepared by diluting 50 mL of 0.10 M HNO3(aq) with water to 500 mL of solution is?

**Solution:**

Amount of substance of $HNO_{3}$ in 50 mL of 0.10 M $HNO_{3}(aq)$ is:

$$\nu(HNO_{3}) = (50 \text{ mL}) \times \left(0.1 \frac{\text{mol}}{\text{L}}\right) = 0.05 \text{ L} \times 0.1 \frac{\text{mol}}{\text{L}} = 0.005 \text{ mol} = 5 \times 10^{-3} \text{ mol}$$

As HNO3 is a strong electrolyte (fully ionized):

$$HNO_{3} \rightarrow +NO_{3}^{-}$$

Thus:

$$\nu(HNO_{3}) = \nu(H^{+})$$

So:

$$M(H^{+}) = \frac{\nu(H^{+})}{500 \text{ mL}} = \frac{5 \times 10^{-3} \text{ mol}}{0.5 \text{ L}} = 0.01 \text{ M}$$

**Answer:** hydrogen ion concentration is 0.01 M