Question

How many moles of CO2 should be placed in a 250 ml container at -24 Celsius to produce a pressure of 95 kPa?​

Answer 1

0.011 mol CO₂

General Formulas and Concepts:

Chemistry - Gas Laws

Combined Gas Law: PV = nRT

• P is pressure
• V is volume (in Liters)
• n is amount of moles
• R is a gas constant -
  `8.314 (L \cdot kPa)/(mol \cdot K)`
• T is temperature (in Kelvins)

Temperature Conversion: K = °C + 273.15

Step-by-step explanation:

Step 1: Define

250 mL

-24°C

95 kPa

Step 2: Identify Conversions

Temp Conversion

1000 mL = 1 L

Step 3: Convert

`250 \ mL((1 \ L)/(1000 \ mL) )` = 0.25 L

-24°C + 273.15 = 249.15 K

Step 4: Find Moles

1. Substitute:
   `(95 \ kPa)(0.25 \ L) = n(8.314 (L \cdot kPa)/(mol \cdot K))(249.15 \ K)`
2. Isolate n:
   `((95 \ kPa)(0.25 \ L) )/((8.314 (L \cdot kPa)/(mol \cdot K))(249.15 \ K)) = n`
3. Rewrite:
   `n = ((95 \ kPa)(0.25 \ L) )/((8.314 (L \cdot kPa)/(mol \cdot K))(249.15 \ K))`
4. Evaluate:
   `n = 0.011465 \ mol \ CO_2`

Step 5: Check

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

0.011465 mol CO₂ ≈ 0.011 mol CO₂