HCl+NaOH -- H2O+NaCl, how many moles of acid were in the sample?
I made an editorial correction from your initial formula of "NCl"; when I looked at the products, there was no "N" to be found, so it made much more sense that it should have been "HCl" instead. The mole is commonly calculated to be the atomic mass units for one molecule of that substance. So the H would be 1 gram, added to the 35.5 grams for chlorine, which would give 36.5 grams for the acid, which is hydrochloric acid. The equation is balanced as it is, so no coefficients are needed to increase the number of moles. Moles are accounted for in proportion to each other in the total equation, so since it is a one to one ratio (1:1), 36.5 moles of hydrochloric acid would be the answer. This is a very familiar chemistry equation where you add a strong acid to a strong base and produce a salt plus water as products. The reactants are listed on the left of the yields sign; those are the substances you start with, the acid and the base. The products are on the right of the yields sign; that would be the water and the salt.