Respuesta :

determine the mol ratio of both the reagents
Then calculate the mol for both reagents
eg NaOH + HCl --> NaCl + H2O
given in qns NaOH is 5g and 50cm^3 of 0.2mol/dm^3 HCL

from eqn:
Mole ratio of NaOH to HCL = 1:1

from calculations:
no. of mole of NaOH = 5 / (23+16 +1) = 0.125mol (excess)
no. of mole of HCL = 0.2 * 50/1000 =0.01 mol (limiting)

NaOH : HCL should equals to 1:1 however from calculations it is not 1:1 and n(HCL) < n(NaOH) HCL limiting, NaOH excess