Question

If 5.0 liters H2 (g) at STP is heated to a temperature of 985, pressure remaining constant, the new volume of the gas will be?

Answer 1

`V_2=18 \ L \ H_2`

General Formulas and Concepts:

Chemistry - Gas Laws

• STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K
• Charles' Law:
  `(V_1)/(T_1) =(V_2)/(T_2)`

Step-by-step explanation:

Step 1: Define

Initial Volume: 5.0 L H₂ gas

Initial Temp: 273 K

Final Temp: 985 K

Final Volume: ?

Step 2: Solve for new volume

1. Substitute:
   `(5 \ L \ H_2)/(273 \ K) =(x \ L \ H_2)/(985 \ K)`
2. Cross-multiply:
   `(5 \ L \ H_2)(985 \ K) = (x \ L \ H_2)(273 \ K)`
3. Multiply:
   `4925 \ L \ H_2 \cdot K = 273x \ L \ H_2 \cdot K`
4. Isolate x:
   `18.0403 \ L \ H_2 = x`
5. Rewrite:
   `x=18.0403 \ L \ H_2`

Step 3: Check

We are given 2 sig figs as the smallest. Follow sig fig rules and round.

`18.0403 \ L \ H_2 \approx 18 \ L \ H_2`