Verified answer

Объяснение:

Дано:

w(NaOH)=20%

m(NaOH)=20г

w(НСОOH)=?

HCOOH + NaOH = HCOONa + H2O

m(NaOH)= m(розч)•w(NaOH)=20•0.2=4г

M(NaOH)=23+16+1=40г/моль

n(NaOH)=m/M=4/40=0.1моль

n(NaOH)=n(HCOOH)

M((HCOOH)=1+12+2•16+1=46г/моль

m(HCOOH)= n•M=0.1•46=4.6г