Question

if you have 2 moles of water, how many grams is that?
a. 22.99 grams
b. 18.02 grams
c. 44.00 grams
d. 36.04 grams

Explanation:

Step1: Calculate molar mass of water ($H_2O$)

Molar mass of $H = 1.008\ g/mol$, molar mass of $O=16.00\ g/mol$.
Molar mass of $H_2O=(2\times1.008 + 16.00)\ g/mol=18.016\ g/mol\approx18.02\ g/mol$

Step2: Calculate mass of 2 moles of water

Use the formula $m = n\times M$ (where $m$ is mass, $n$ is number of moles, $M$ is molar mass).
Given $n = 2\ mol$, $M\approx18.02\ g/mol$
$m=2\ mol\times18.02\ g/mol = 36.04\ g$

Answer:

d. 36.04 grams