Question

1. Calculate the pressure, in atm, required to compress a sample of helium gas from 20.9 L (at 1.00 atm) to 4.00L B) 83.6 D) 24.1 A) 5.2 C) 0.19 A balloon measuring 1.25 L at 20°C is heated to 80°C what is its new volume? A) 1.5 C) 5 2. B) 0.3125 D) 1.0 When the temperature outside is 30.0°C, my car's tires have a pressure of 2.05 atm. What pressure will they have when the temperature is 2.0°C? A) 30 3. B) 0.14 D) 1.86 C) 29 4. A balloon occupies 2.50 L at 25 C and 1.00 atm. What is the volume when the pressure is changed to 0.800 atm and the temperature to 20°C? A) 2.5 C) 3.1 B) 3.2 D) 275.65 5. Calculate the volume of 22.0 g of CO2 at STP A) 12.05 C) 24.1 B) 11.2 D) 22.4

Answer 1

Mole of CO_2 = Given mass/Molar mass = 22 g/44.01 g/moL = 0.49 moL No. of mol of CO_2 = volume of gas/22.4 L moL^-1 0.49 moL = volume of gas/22.4 L moL^-1 Volume of gas = 0.49 moL times 22.4 L moL^-1 = 11.2 L Option B correct \r\n From Boyle�s law of Pressure is inversely proportional to volume at constant Temperature and mole. P alpha V p = K/V where K = constant PV = K So P_1 V_1 = P_2 V_2 P_1 = initial pressure 20.9 L times 1 atm = P_2 times 4.00 L V_1 initial volume 20.9 L times 1 atm/4.00 L = P_2 P_2 = final pressure V_2 = final volume 5.225 atm = P_2 So pressure (P_2) = 5.2 atm option A correct. From Charles law V_1 /T_1 = V_2 /T_2 where T is in Kelvin T(K) = T degree C + 273.15 = 20 + 273.15 = 293.15 K For 80 degree