Question

What is the molarity of a solution made from 0.250 mol of sodium hydroxide and 500 mL of water?

Answer 1

`\boxed {\boxed {\sf 0.5 \ M \ NaOH}}`

Step-by-step explanation:

Molarity is a measure of concentration in moles per liter.

`molarity= (moles)/(liters)`

There are 0.250 moles of sodium hydroxide (NaOH) and 500 milliliters of water. We need to convert milliliters to liters. Remember that 1 liter contains 1000 milliliters.

`(1 \ L)/(1000 \ mL)`

`500 \ mL*(1 \ L)/(1000 \ mL)`

`500*(1 \ L)/(1000 )`

`(500)/(1000) \ L=0.5 \ L`

Now we have the values to solve for molarity:

• moles= 0.250 mol NaOH
• liters= 0.5 L

Substitute the values into the formula.

`molarity= (0.250 \ mol \ NaOH)/(0.5 \ L)`

Divide.

`molarity= 0.5 \ mol \ NaOH/ L`

• 1 mole per liter (mol/liter) is equal to 1 Molar or M.
• Our answer of 0.5 moles of sodium hydroxide per liter is equal to 0.5 M NaOH

`molarity= 0.5 \ M \ NaOH`

The molarity of the solution is 0.5 M NaOH