Question

the following solutions are added together: .5l of .5m hcl, 300 ml of .2m naoh, and 100ml of .4m ca(oh)2. calculate the concentration of the excess acid or base

Answer 1

`C=0.122M`

Step-by-step explanation:

Total volume:

`V= 0.5 L + 0.3 L + 0.1 L=0.9 L`

Total acid (H+) moles:

`n_(acid)=0.5 L * 0.5 mol/L=0.25 mol`

Total base (OH-) moles:

`n_(base)=0.3 L*0.2 mol/L + 0.1 L*0.4mol/L*2=0.14mol`

Excess acid:

`n_(ex)=0.25 mol - 0.14mol=0.11 mol`

Concentration:

`C=(0.11mol)/(0.9L)=0.122M`