Question

Question #b80cc

Answer 1

`0.066"mol/l"`

Explanation:

`H_3PO_(4(aq))+3NaOH_((aq))rarrNa_3PO_(4(aq))+3H_2O_((l))`

No. moles `NaOH=cxxv=0.250xx0.0425=0.01`

From the equation we can see that the no. moles of phosphoric acid must be 1/3 of this:

`:.nH_3PO_4=0.01/3=0.0033`

`c=n/v`

So the concentration of the `H_3PO_4` is given by:

`c=0.0033/0.05=0.066"mol/l"`