Question

Find the number of millimoles for 0.160 g sodium hydroxide.

• A. 0.08
• B. 0.20
• C. 4.00
• D. 40.00

Hint:

$\text{Millimoles} = \frac{\text{Mass in grams}}{\text{Molar mass}} \times 1000$.

Answer 1

The Correct Option is C

Step 1: Molar Mass
Molar mass of NaOH = $23 (Na) + 16 (O) + 1 (H) = 40$ g/mol.
Step 2: Calculate Moles
$\text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}} = \frac{0.160}{40} = 0.004$ moles.
Step 3: Convert to Millimoles
$\text{Millimoles} = \text{Moles} \times 1000 = 0.004 \times 1000 = 4.0$.
Step 4: Conclusion
The number of millimoles is 4.00.
Final Answer:(C)