Calculate the mass of the salt formed by the interaction of 80 g of sodium hydroxide with hydrochloric acid.

Given:
m (NaOH) = 80 g
Find:
m (salt) =?
Solution:
1) Let’s compose the equation of the chemical reaction, let the mass of the salt be x g.
HCl + NaOH = NaCl + H2O
2) Find the molecular weights of hydrochloric acid and sodium chloride.
M (NaOH) = 23 + 16 + 1 = 40 g / mol
M (NaCl) = 23 + 35.5 = 58.5 g / mol
3) 80 g: 40 g / mol = x g: 58.5 g / mol
x = (80 x 58.5): 40 = 117 g.
Answer: m (salt) = 117 g.