Question

What is the molarity (M) of 1 liter of a solution that has 120 g of NaCl dissolved in it?

Answer 1

2.05 M

Step-by-step explanation:

Molarity is defined as number of moles of solute in 1 L of solution.

Molarity =
`(Number\ of\ moles\ of\ solute)/(Volume\ of\ solution\ in\ L)`

Here we have 120 g of NaCl in 1 liter of solution.

Molar mass of NaCl = 58.5 g

Number of moles of NaCl =
`(Given\ mass\ of\ solute)/(Molar\ mass\ of\ solute)` =
`(120)/(58.5)=2.05\ moles`

Volume of solution = 1 L

Molarity =
`(Number\ of\ moles\ of\ solute)/(Volume\ of\ solution\ in\ L)=(2.05)/(1)=2.05\ moles\ per\ litre`

Answer 2

The answer to your question is 2.1

Step-by-step explanation:

Data

Molarity = 1 l

mass = 120 g of NaCl

moles = ?

Formula

`Molarity = (number of moles)/(Volume)`

Process

1.- Calculate the number of moles of NaCl

Molecular weight NaCl = 23 + 35.5 = 58.5 g

2.- Calculate the number of moles using proportions

58.5 g of NaCl --------------- 1 mol

120.0 g of NaCl --------------- x

x = ( 120 x 1) / 58.5

x = 2.1 moles

3.- Calculate Molarity

Substitution

`Molarity = (2.1)/(1)`

Simplification and result

Molarity = 2.1