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Answer:

Explanation:
Hello,
In this case, for the given reactants we identify the following chemical reaction:

Thus, we evidence a 1:1 molar ratio between KOH and HCl, therefore, for the complete neutralization we have equal number of moles, that in terms of molarities and volumes become:

Hence, we compute the volume of HCl as shown below:

Best regards.
Answer:
[NaCl[ = 0.535M
Explanation:
We determine the moles of solute:
125 g . 1 mol/ 58.45 g = 2.14 moles
Molarity (mol/L) → 2.14 mol / 4L → 0.535M
Molarity is a sort of concentration that indicates the moles of solute in 1L of solution