Question

What is the volume of 40.0 grams of argon gas at STP ?

Answer 1

24.9 L Ar

General Formulas and Concepts:

Atomic Structure

• Reading a Periodic Table
• Moles
• STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K

Aqueous Solutions

• States of Matter

Stoichiometry

• Using Dimensional Analysis

Step-by-step explanation:

Step 1: Define

[Given] 40.0 g Ar

[Solve] L Ar

Step 2: Identify Conversions

[PT] Molar Mass of Ar - 39.95 g/mol

[STP] 22.4 L = 1 mol

Step 3: Convert

1. [DA] Set up:
   `\displaystyle 40.0 \ g \ Ar((1 \ mol \ Ar)/(39.95 \ g \ Ar))((22.4 \ L \ Ar)/(1 \ mol \ Ar))`
2. [DA] Divide/Multiply [Cancel out units]:
   `\displaystyle 24.9235 \ L \ Ar`

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

24.9235 L Ar ≈ 24.9 L Ar