Question

0.090 moles of sodium sulfate is dissolved in a 12 ml solution. what is the molarity of the solution?

• your answer should have two significant figures (round your answer to one decimal place).
• do not include units in your response.

Explanation:

Step1: Convert volume to liters

$$12\ \text{mL}=12\times10^{-3}\ \text{L}=0.012\ \text{L}$$

Step2: Calculate molarity

Molarity formula is $M = \frac{n}{V}$ (where $n$ is moles and $V$ is volume in liters).
Substitute $n = 0.090$ moles and $V=0.012$ L:
$$M=\frac{0.090}{0.012}=7.5$$

Answer:

7.5