CH3COOH+NaOH-->CH3COONa+H2O

m (NaOH) = m раствора (NaOH) x W (NaOH) = 120 x 0,25 = 30 г

n (NaOH) = m (NaOH) / M (NaOH) = 30 /40 = 0,75 моль

n (CH3COOH) = n (NaOH) = 0,75 моль

m (CH3COOH) = n (CH3COOH) x M (CH3COOH) = 0,75 x 60 =45 г  

1) m (NaOH)=W(раствора)*m(раствора)

    m (NaOH)=0.25*120г=30г

2)  n (NaOH) = m (NaOH)/M(NaOH)

M(NaOH) = 23+16+1=40г/моль

     n (NaOH) = 30г/40г/моль=0,75моль

3)   n (NaOH) =n(CH3COOH)=0,75моль

4)m (CH3COOH) = M (CH3COOH)*n(CH3COOH)

M (CH3COOH) = 12+1*3+12+16+16+1=60г/моль

m (CH3COOH) = 60 г/моль*0,75моль = 45 г