Question

What is the mass in grams of a sample of 7.3 x 10^23 molecules of (iodine heptafluoride) IF7

Answer 1

320 g IF₇

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

Atomic Structure

• Reading a Periodic Table
• Using Dimensional Analysis
• Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Step-by-step explanation:

Step 1: Define

7.3 × 10²³ molecules IF₇

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of I - 126.90 g/mol

Molar Mass of F - 19.00 g/mol

Molar Mass of IF₇ - 126.90 + 7(19.00) = 259.9 g/mol

Step 3: Convert

1. Set up:
   `\displaystyle 7.3 \cdot 10^(23) \ molecules \ IF_7((1 \ mol \ IF_7)/(6.022 \cdot 10^(23) \ molecules \ IF_7))((259.9 \ g \ IF_7)/(1 \ mol \ IF_7))`
2. Multiply/Divide:
   `\displaystyle 315.056 \ g \ IF_7`

Step 4: Check

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

315.056 g IF₇ ≈ 320 g IF₇