A sample of gas occupies 100 ml at 27oC and 740 mm pressure. When its volume is changed to 80 ml at — States of Matter and Gaseous State Chemistry Question

💡 Solution & Explanation

# Gas Law Problem Solution **Given Information:** - Initial: $V_1 = 100$ ml, $T_1 = 27°C = 300$ K, $P_1 = 740$ mm - Final: $V_2 = 80$ ml, $T_2 = ?$, $P_2 = 740$ mm **Step 1: Identify the applicable law** Since pressure remains constant ($P_1 = P_2$), this is an **isobaric process**. Use Charles's Law: $$\frac{V_1}{T_1} = \frac{V_2}{T_2}$$ **Step 2: Substitute values** $$\frac{100}{300} = \frac{80}{T_2}$$ **Step 3: Solve for $T_2$** $$T_2 = \frac{80 \times 300}{100} = \frac{24000}{100} = 240 \text{ K}$$ **Step 4: Convert to Celsius** $$T_2 = 240 - 273 = -33°C$$ **Answer:** The final temperature is **240 K or –33°C** (option C) The volume decreased proportionally, so temperature must also decrease proportionally at constant pressure, confirming our result.