Question

36. The temperature of a 500 mL sample of gas increases from 150. K to 350. K. What is the final volume of the sample of gas, if the pressure and amount of gas remains the same? A. 1170 mL B. 210 mL C. 110 mL D. 0.0950 mL 37. At 570. mmHg and 25 °C, a gas has a volume of 2270 mL. What is the final pressure (in mmHg) at a volume of 1250 mL and a temperature of 175 °C? A. 1560 mmHg B. 690 mmHg C. 470 mmHg D. 210 mmHg A1 of CH4 and 2.0 g of He. What is the volume at STP?

Answer 1

(36) To find the final volume of the gas According to charles'law T, T, where Vi = initial volume T = initial temperature V = final volume Tg = final temperature Vi = 500mL T, = 150K V, = ? T, = 350K Vi V; T, T, 500mL V 150K 350K Cross multiplication are allowed 500mL X350K = V, 150K v 500mL X350K 150K = 1170mL Hence the final volume of the gas = 1170mL Answer is option (A)

(37) To find the final pressure According to combined gas law PV, PV T, T, where P = initial pressure V = initial volume T = initial temperature Py = final pressure V = final volume Tg = final temperature Given that P1 = 570mm Hg P₂ = ? Vi = 2270mL V, = 1250 mL Change the temaparature to kelvin Ty = 25+273= 298K Ty = 175 +273 = 448K BV BV TI 570 mm Hg x 2270mL_Pjx1250 mL 298K 448K Cross multiplication are allowed 570 mmHg x 2270mL x 448K = P, x1250 mL x 298K 570 mm Hg x 2270mL x 448K 1250mL x 298K 570x2270x448 1250x298mmHg Py = 1556mmHg Hence the final pressure = 1556mmHg Answer is option (A) P =