Answer: 10.62g
Step-by-step explanation:
First let us generate a balanced equation for the reaction.
HCl + NaOH —> NaCl + H2O
Molar Mass of HCl= 1 + 35.5 = 36.5g/mol
Molar Mass of NaOH = 23 + 16 + 1 = 40g/mol
From the question,
Mass of HCl = 17g
Mass of NaOH = 6.99g
Converting these Masses to mole, we obtain:
n = Mass / Molar Mass
n of HCl = 17/36.5 = 0.4658mol
n of NaOH = 6.99/40 = 0.1748mol
From the question,
1 mole of NaOH requires 1mole of HCl.
Therefore, 0.1748mol of NaOH will also require 0.1748mol of HCl.
But we were told that 17g( i.e 0.4658mol) of HCl were mixed.
Therefore, the unreacted amount of HCl = 0.4658 — 0.1748 = 0.291mol
Converting this to mass, we have:
Mass of HCl = n x molar Mass
Mass of HCl = 0.291 x 36.5
Mass of HCl = 10.62g
Therefore the left over Mass of HCl is 10.62g