Question

How many moles of water are present in 180 g of water?

• A. 1 mole
• B. 18 moles
• C. 10 moles
• D. 100 moles

Hint:

Always divide the given mass of a substance by its molar mass to calculate moles.

Answer 1

The Correct Option is C

Step 1: Formula for number of moles.
\[ \text{Number of moles} = \frac{\text{Given mass}}{\text{Molar mass}} \]
Step 2: Molar mass of water.
Molar mass of H$_2$O = $2 \times 1 + 16 = 18$ g mol$^{-1}$.

Step 3: Substitution.
\[ \text{Number of moles} = \frac{180}{18} = 10 \]
Step 4: Conclusion.
Thus, 180 g of water contains 10 moles.

Final Answer: \[ \boxed{10 \ \text{moles}} \]