Question

May someone assist, please...? I don't know how to do chemistry work...

Answer 1

All questions can be solved by C1V1=C2V2

1) 5.00M x V1 = 0.900M x 500.0 mL

V1= 90 ml

therefor you need to add 500 - 90 = 410.0 ml

2) 20.0 mL x C1 = 150.0mL x 1.50 M

C1= 11.25 M

3) 12.00 mL x 3.50 M = 100.0 mL x C2

C2= 0.42 M

4) 9.0 mL x 8.0 M = 0.50 M x V2

V2 = 144 ml