Question

What would be the mass of 9.03 x 10^21 molecules of hydrobromic acid?

Answer 1

1.21 g HBr

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

Compounds

• Writing Compounds
• Acids/Bases

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

9.03 × 10²¹ molecules HBr

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of H - 1.01 g/mol

Molar Mass of Br - 79.90 g/mol

Molar Mass of HBr - 1.01 + 79.90 = 80.91 g/mol

Step 3: Convert

1. Set up:
   `\displaystyle 9.03 \cdot 10^(21) \ molecules \ HBr((1 \ mol \ HBr)/(6.022 \cdot 10^(23) \ molecules \ HBr))((80.91 \ g \ HBr)/(1 \ mol \ HBr))`
2. Multiply/Divide:
   `\displaystyle 1.21325 \ g \ HBr`

Step 4: Check

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

1.21325 g HBr ≈ 1.21 g HBr