Adipic acid is di - protic:
#sf(H_2X+2NaOHrarrNa_2X+2H_2O)#
#sf(M_r=146.14)#
The no. moles of #sf(H_2X)# is given by:
#sf(n_(H_2X)=m/M_r=0.283/146.14=0.0019365)#
From the equation we can say that the no. moles of #sf(NaOH)# must be twice that:
#sf(n_(NaOH)=2xx0.0019365=0.003873)#
#sf(c=n/v)#
#:.##sf(v=n/c=0.003873/0.1000=0.03373color(white)(x)L)#
#sf(v=38.73color(white)(x)ml)#
(b)
Now the acid is 74% pure:
#sf(m_(H_2X)=0.304xx0.74=0.22496color(white)(x)g)#
#sf(n_(H_2X)=m/M_r=0.22496/146.14=0.00153934)#
#:.##sf(n_(NaOH)=0.00153934xx2=0.00307869)#
#sf(v=n/c=0.0030786/0.1000=0.0307869color(white)(x)L)#
#sf(v=30.79color(white)(x)ml)#