A gas occupies 1 L at 27°C. If the pressure is held constant, what is its volume at 40°C? Use 273.15 for the conversion from Celsius to Kelvin.

Charles's Law states that for a fixed amount of gas at constant pressure, the volume is directly proportional to its absolute temperature. The formula is:

$$\frac{V_1}{T_1} = \frac{V_2}{T_2}$$

Rearranging to solve for $V_2$:

$$V_2 = V_1 \times \frac{T_2}{T_1}$$

Gas law calculations require temperatures to be in Kelvin.

$$T_K = T_C + 273.15$$

Given:
$V_1 = 1 \text{ L}$
$T_1 = 27^\circ \text{C}$
$T_2 = 40^\circ \text{C}$

Convert $T_1$:

$$T_1 = 27^\circ \text{C} + 273.15 = 300.15 \text{ K}$$

Convert $T_2$:

$$T_2 = 40^\circ \text{C} + 273.15 = 313.15 \text{ K}$$

$$V_2 = 1 \text{ L} \times 1.043305...$$ $$V_2 \approx 1.04 \text{ L}$$

The final volume is:

$$\text{1.04 L}$$