Question

A cylinder full of helium gas is placed in a storage room at a temperature of IS °C. The volun cylinder is 20.0 L and the gas initially has a pressure of 100.0 atm. A. How many moles of helium gas are initially in the cylinder? B. What is the mass of the helium in the cylinder? C. A small fire breaks out in the storage room, raising the the to 450 °C. If the so that no gas escapes, what is the new pressure that builds up inside of it? 2GH(g)+s0,(g)-4C0,(@)+2H,0g) + 2600k B. If 5.00 g of acetylene are burned with excess oxygen, how many moles of CO, are produced? when the 5.00 g of acetylene is burned? C. How much energy is produced

Answer 1

Considering helium as an ideal gas we can apply the ideal gas equation PB = nRT Given, T = 15 c degree = (15 + 273) k = 288 k V = 20.0L P = 100.0 atm R = 0.82057 L atm mol^- 1 k^- 1 A. n = Pv/RT = 100.atm times 20.0 L/0.082057 L atm mol^- 1 k^- 1 times 288 k = 84.6 therefore 84.6 mol of helium gas are initially in the cylinder B. We know, 1 mol helium gas = 4.003 g therefore 84.6 mol helium gas = 84.6 times 4.003/1 g = 338.7 g therefore Mass of helium in cylinder is 338.7 g \r\n c. P = nRt/v = 84.6 mol times 0.082057 L atm mol^- 1 k^- 1 times (450 + 273) k/20.0L = 250.95 atm therefore The new pressure is 250.95 atm. 24. A) As heat