Calculate the mass of NaCl that is obtained by reacting 200 grams of NaOH solution (W = 8%) b HCl.

NaOH + HCl = NaCl + H2O.

First, let’s calculate how much g of NaOH enters into the reaction (since the mass fraction and mass of the solution are known):

w = x / 200 * 100% = 8%.

Hence x = 16 g.

That is, it is necessary to determine the mass of NaCl formed from 16 g of NaOH. To do this, we will compose the proportion, taking into account that 58.4 g of NaCl is formed from 40 g of NaOH:

16 g – x g

40 g – 58.4 g

x = 16 * 58.4 / 40 = 23.4 g.

Thus, the mass of NaCl is 23.4 g.