Question

What is the molarity of a solution containing 3.6 mol of KCl in 750 mL?

Answer 1

`\boxed {\boxed {\sf 4.8 \ M \ KCl}}`

Step-by-step explanation:

The molarity of a solution is found by dividing the moles of solute by the liters. of solvent.

`molarity=(moles)/(liters)`

We know the solution has 3.6 moles of potassium chlorine. We know there are 750 milliliters of solvent, but we need to convert this to liters.

• 1 liter is equal to 1000 milliliters. Set up a proportion.

• 
  `\frac {1 \ L }{1000 \ mL}`

• Multiply by 750 mL and the units of mL will cancel.

• 
  `750 \ mL * \frac {1 \ L }{1000 \ mL} = \frac {750 \ mL}{1000 \ mL}= 0.75 \ L`

Now we know the moles and liters, so we can calculate molarity.

• moles= 3.6 mol KCl
• liters= 0.75 L

Substitute these values into the formula.

`molarity= (3.6 \ mol \ KCl)/(0.75 \ L)`

Divide.

`molarity= 4.8 \ mol \ KCl/ L`

• 1 mole per liter is equal to 1 molar.
• Our answer of 4.8 moles of potassium chloride per liter is equal to 4.8 M KCl

`molarity= 4.8 \ M \ KCl`

The molarity of the solution is 4.8 M KCl.