Question

What is the molarity of a solution in which 7.1 g of sodium sulfate is dissolved in enough water to make 100. mL of solution?

Answer 1

0.5 M

Step-by-step explanation:

Hello,

In this case, since sodium sulfate molar mass is 142.04 g/mol we first need to compute the moles in 7.1 g as shown below:

`n=7.1g*(1mol)/(142.04 g) =0.050mol`

Then, since 100 mL are 0.1 L the molarity turns out:

`M=(n)/(V)=(0.05mol)/(0.1L)\\\\M=0.5M`

Regards.

Answer 2

0.50 M

Step-by-step explanation:

Given data

• Mass of sodium sulfate (solute): 7.1 g

• Volume of solution: 100 mL

Step 1: Calculate the moles of the solute

The molar mass of sodium sulfate is 142.04 g/mol. The moles corresponding to 7.1 grams of sodium sulfate are:

`7.1g * (1mol)/(142.02g) = 0.050mol`

Step 2: Convert the volume of solution to liters

We will use the relation 1 L = 1000 mL.

`100mL * (1L)/(1000mL) =0.100L`

Step 3: Calculate the molarity of the solution

`M = (moles\ of\ solute )/(liters\ of\ solution) = (0.050mol)/(0.100L) =0.50 M`