Question

chemistry 20 stoichiometry quiz
name: ebtesam
multiple choice

1. what is the molar mass of aluminum sulfate?

□ 342.17 g/mol
□ 342.17 g
□ 123.05 g
□ 123.05 g/mol

Explanation:

Step1: Determine the formula of aluminum sulfate

The formula is $Al_2(SO_4)_3$.

Step2: Find the molar mass of each element

Aluminum (Al): molar - mass of Al is $26.98\ g/mol$, and there are 2 Al atoms. Sulfur (S): molar - mass of S is $32.07\ g/mol$, and there are 3 S atoms. Oxygen (O): molar - mass of O is $16.00\ g/mol$, and there are 12 O atoms.

Step3: Calculate the molar mass of aluminum sulfate

\[

$$\begin{align*} M&=2\times26.98\ g/mol+3\times32.07\ g/mol + 12\times16.00\ g/mol\\ &=53.96\ g/mol+96.21\ g/mol+192.00\ g/mol\\ &=342.17\ g/mol \end{align*}$$

\]

Answer:

342.17 g/mol