Question

What would be the mass of 9.65x1025 molecules of water​

Answer 1

2890 g H₂O

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
• Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

• Using Dimensional Analysis

Step-by-step explanation:

Step 1: Define

9.65 × 10²⁵ molecules H₂O (water)

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of H - 1.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol

Step 3: Convert

1. Set up:
   `\displaystyle 9.65 \cdot 10^(25) \ molecules \ H_2O((1 \ mol \ H_2O)/(6.022 \cdot 10^(23) \ molecules \ H_2O))((18.02 \ g \ H_2O)/(1 \ mol \ H_2O))`
2. Divide/Multiply:
   `\displaystyle 2887.63 \ g \ H_2O`

Step 4: Check

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

2887.63 g H₂O ≈ 2890 g H₂O