.4g sample of monobasic acid requires 16cm3 of .1 mol dm 3 of NAOH for complete neutralization what is relative mass of acid
2 answers
250
Monobasic acid has only 1 replaceable hydrogen atom:
Thus, let it be rep as HX:
Equation of rxn:
HX + NaOH ------> NaX + H2O
Mole ratio: na/nb = 1/1, then;
CaVa = CbVb
Vb = 16cm3 = 0.016dm3
Cb = 0.1mol/dm3
Mass of acid = 0.4g
Where CbVb = Nb,
0.016 x 0.1 = 0.0016moles
Since na = nb,
0.0016moles = na
Nos of moles = used mass/molar mass
0.0016 = 0.4/molar mass
Molar mass = 0.4/0.0016 = 250g/mol
= 250g/mol
Thus, let it be rep as HX:
Equation of rxn:
HX + NaOH ------> NaX + H2O
Mole ratio: na/nb = 1/1, then;
CaVa = CbVb
Vb = 16cm3 = 0.016dm3
Cb = 0.1mol/dm3
Mass of acid = 0.4g
Where CbVb = Nb,
0.016 x 0.1 = 0.0016moles
Since na = nb,
0.0016moles = na
Nos of moles = used mass/molar mass
0.0016 = 0.4/molar mass
Molar mass = 0.4/0.0016 = 250g/mol
= 250g/mol
2 answers