Question

1. A 10.0 L gas sample is heated to 400 ◦C at P = constant. The final volume is 20.0 L. What is the initial temperature of this gas? Assume ideal-gas behavior and a constant amount of gas throughout the process (n, P = constant). T(K) = T(◦C) + 273.

(A) 63.5 ◦C

(B) 73 ◦C

(C) 200 ◦C

(D) 336.5 ◦C

(E) 609.5 ◦C

2. A gas cylinder can safely handle pressures up to 75.0 atm. If the gas pressure in the cylinder is 63.3 atm at 15 ◦C, what is the highest safe temperature for this cylinder? Assume ideal-gas behavior and V, n = constant. T(K) = T(◦C) + 273.

(A) 17.8 ◦C (B) 68 ◦C (C) 243 ◦C (D) 291 ◦C (E) 341 ◦C

3. At 1 atm, dioxygen O2 is solid below −218.8 ◦C, liquid between −218.8 and −183.0 ◦C, and gaseous above −183.0 ◦C. At 1 atm, O2 will follow the ideal-gas law most closely

(A) above +80.0 ◦C. (B) between −20.0 and +10.0 ◦C. (C) between −183.0 and −80.0 ◦C.(D) close to −183.0 ◦C. (E) below −183.0 ◦C.

Answer 1

1) According to Charless law, volume of the gasis directly proportional to absolute temperature at constant pressure να Τ = constant HSK -- Fortwo gasses, T I --- -- ------ -------- ------ ---------- Initi al volume of the gas, V = 10.0L Initi al temperature of the the gas=7; Final temperature of the gas = 7; = 400 °C +273 = 673 K Final volume of the of the the gas, Vj = 20.0L According to Charlesslaw, Initi al temperature of gas, T=7(1) = 336.5 K-273 = 63.5°C