STP – Standard Temperature and Pressure. T=273 K, P=1atm.   1.       A 113L sample of helium at 27°C is cooled at constant pressure to -78. 0°C. Calculate the new volume of the helium.   2.       Determine the volume of occupied by 2. 34 grams of carbon dioxide gas at STP.   3.       Under what pressure is the gas in the vessel if the rms velocity of its molecules is v = 103 m/s, the concentration of molecules is n = 3∙1025 m-3, the mass of each molecule is m0 = 5 ∙ 10-26 kg?   4.      A 12. 0 g sample of gas occupies 19. 2 L at STP. What is the molecular weight of this gas?   5.       What mass of CO2 is needed to fill an 80. 0 L tank to a pressure of 150. 0 atm at 27. 0°C?   6.       2. 035 g H2 produces a pressure of 1. 015 atm in a 5. 00 L container at -211. 76 °C. What will the temperature (in °C) have to be if an additional 2. 099 g H2 are added to the container and the pressure increases to 3. 015 atm.   7.       The concentration of gas molecules is n = 2. 7 · 1025 m-3. Gas produces a pressure p = 105 Pa on the walls of the vessel. What is the average kinetic energy E of the translational motion of molecules? ​