Question

Potassium superoxide (KO2) reacts with carbon dioxide to produce oxygen in reaction is very fast and nearly quantitative. It is used in submarines, space vehicles, space suits, and by firefighters and miners. 4 KO2(s) + 2 CO2(g) - 2 K2CO3(s) + 3 O2(g) Calculate the mass of KO2 reacted if 355.8 mL of gas is collected over water at 65.0 °C and a barometric pressure of 744.8 torr. (12 pts.) 7. When 12.424 g of (NH4),PO. (FW 149.087 g/mole) is dissolved in 200.0 mL of water i a coffee-cup calorimeter, the temperature of the calorimeter goes from 22.76 °C to 18.49 °C. Calculate the AH, in kJ/mole NH4, of the following reaction. (12 pts.) (NH)3PO4(s) — 3 NH4+ (aq) + PO2 (aq)

Answer 1

0 v= 355.4mL = 0.35584 T = 25+273 = 2981 P = 744.5 torr = 0.98ation P. V = nRT 0.98 0.3558= nxo.0821 x 298 n=0.01425 4 mole ką 3 mole o ? -5 0.01425 moleon moly of ko₂ = 4x 0.01425 = 0.0190 3 Mass of KOL = 0.0190 x 71.1 = 1.359 Mass of Ko2 = 1.35g] AT= 22.76 - 18.49 = 4.27C 12.424 = 0.0833 Mdy of salt = 149.087 12.424 +20o = 212.4249 Total mass = 212.424 x 4.184x4-27 Q = mgodt = Q = 3795 J= 3.795 kJ 44 = 3.795 = 15-19 kJ/mol 3 X 0.6633 AH = 1.1 | |