12. Calculate the volume of a 0.45M solution containing 20 g of NaOH.

1.11L

Explanation:

Firstly calculate the molar mass of NaOH, 40+16+1=40g/mol

Number of moles = molarity*volume

Number of moles=mass given/molar mass

Mass given=20g

Molar mass=40

Number of moles=20/40=0.5moles

Molarity=0.45M

Volume=number of moles/molarity

Volume=0.5/0.45

Volume=1.11L

1.11L

Explanation:

To solve this problem, first, let us calculate the number of mole of NaOH as shown below:

Molar Mass of NaOH = 23 + 16 + 1 = 40g/mol

Mass of NaOH = 20g

Number of mole = ?

Number of mole = Mass / Molar Mass

Number of mole of NaOH = 20/40 = 0.5mol

Now we can calculate the volume of the solution as follows:

Molarity = 0.45M

Mole = 0.5mole

Volume = ?

Molarity = mole / Volume

Volume = mole / Molarity

Volume = 0.5/0.45

Volume = 1.11L