Question

sig figs are important in the answers

AN work must be shown to recelve credit. Circle the answers. 1. How many grams of He are present in 750.0 ml of gas at STP 2. Aballoon has a volume of 750 L at 80°C and is 20 C and the pressure is 0.20 atm? pressure of 380 mmHg, what尋the new volume ifthe temperat re . A baloon contains 0.76 moll N.0.18 mol O0.021 mol He and 0026 mol H pressure of N at 0 972 atm What is the partial How many liters of O, ane needed to react with 450g ofOe at STP 5. Explain why the volume of agas needs to increase as the number of moles increases at constant pressure and temperature

Answer 1

l) Volume occupied by 1 moles of a gas at STP 22.4 L Volume of He = 750.0 mL = 0.7500 L Mass occupied by 0.750 L He gas = 0.750 L × 1 mol He 4.003 g × 22.4 L1 mol He = 0.1340 g 2) Initial pressure of the gas, R 380 mmHg iti al temperature, 7 8.0°C+273-281K Initi al volume of the gas, V-750.0 L 760m 152 mmHg Final pressure of the gas, 0.20 atm × Final temperature, T2 = 2.0°C + 273 = 275 K According to the ideal gas equation, 22 Final Volume of the gas, V2 - 1 atm (380 mmHg) (750.0 L) (275 K) (281 K) (152 mmHg) = 1014 L