The conc of NaOH is 0.104M which means that 1000mL solution contains 0.104mol of NaOH, so the amount of moles used in the titration will be

The reaction of NaOH and HCl is one to one so the moles of HCl that were titrated will also be

The Molarity is therefore
I think the effect of increasing temperature would be; the equilbrium will shift back wards. Increase in temperature favors backward reaction since the forward reaction is exothermic and the backward reaction is endothermic. Therefore, the equilibrium will shift back wards, and there will be more reactants (H2 and Cl2) compared to the products
B.2C2H6 + 5O2 >2CO2 +3H2O