Question

20 gm of a mixture of nacl and naoh exactly requires 7.3 gm hcl for complete reaction.the mass percent of nacl in original mixture is

Answer 1

for complete reaction or neutralisation,
gm. equivalent of mixture = gm. equivalent. of HCl
NaCl is a neutral salt, so it won't react with HCl.
only NaOH reacts with HCl.
so, gm. equivalent. of NaOH = gm. equivalent of HCl
now, gm. equivalent = moles × n-factor
so, mass of NaOH/ 40 ×1 = 7.3/36.5 ×1
mass of NaOH = 0.2×40 = 8gm.
so, mass of NaCl present = 20-8 =12gm
mass percent = 12/20×100 = 60%