Question

A sample of helium gas occupies 1521mL at 719 mmHg. For a gas sample at constant temperature determine the volume of helium at 745 mmHg.

Answer 1

A sample of helium gas occupies $1521\mathrm{mL}$ at $719\mathrm{mmHg}$. For a gas sample at constant temperature determine the volume of helium at $745\mathrm{mmHg}$.

Solution

If the sample is at constant temperature we're dealing with isothermal process, so volume for this process can be found as follows:

$$p_1V_1 = p_2V_2, \quad p\text{ - pressure of helium}$$ $$V\text{ - volume of helium}$$ $$V_2 = \frac{p_1V_1}{p_2}; \quad V_2 = \frac{719\mathrm{mmHg} \cdot 1521\mathrm{mL}}{745\mathrm{mmHg}} = 1467.9\mathrm{mL}$$

Answer: $1467.9\mathrm{mL}$