Question

2Na + Cl2 → 2NaCl

How many moles of Cl2 do you need to use in order to react with 34.485 g of Na?

moles (put 1 zero in front of the decimal)

Answer 1

`\displaystyle 0.75 \ mol \ Cl_2`

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Chemistry

Stoichiometry

• Reading a Periodic Table
• Using Dimensional Analysis

Step-by-step explanation:

Step 1: Define

[RxN] 2Na + Cl₂ → 2NaCl

[Given] 34.485 g Na

Step 2: Identify Conversions

[RxN] 2 mol Na = 1 mol Cl₂

Molar Mass of Na - 22.99 g/mol

Step 3: Stoichiometry

1. Set up:
   `\displaystyle 34.485 \ g \ Na((1 \ mol \ Na)/(22.99 \ g \ Na))((1 \ mol \ Cl_2)/(2 \ mol \ Na))`
2. Multiply/Divide:
   `\displaystyle 0.75 \ mol \ Cl_2`

Step 4: Check

Follow sig fig rules and round. We are given 5 sig figs.

Since our final answer has 2 sig figs, there is no need to round.