Question

What is the molarity of a solution made by mixing 75.0 mL of 3.00 M NH₄OH with enough water to give 250. mL of solution?

Please explain and show work.

Answer 1

• M1=3M
• M2=?
• V1=75mL
• V2=250mL

We know

`\boxed{\Large{\sf M_1V_1=M_2V_2}}`

`\\ \Large\sf\longmapsto M_2=(M_1V_1)/(V_2)`

`\\ \Large\sf\longmapsto M_2=(3(75))/(250)`

`\\ \Large\sf\longmapsto M_2=(225)/(250)`

`\\ \Large\sf\longmapsto M_2=0.9M`

Answer 2

Mass 1=3M

Mass 2=?

Volume1=75mL

Volume2=250mL

By using molarity formula:

mass1*volume 1=mass2*volume 2

3M*75=mass2*250

mass2=225/250

mass2:0.9M

the molarity of a solution is 0.9M.