how is this type of question solved?

The percentage purity of the sodium hydroxide will be 37.5%.option A is correct.
Mass percentage is the amount of solute present in per hundred gram of a solution is called Mass percentage of solution.
Mass percentage = mass of component / mass of solution × 100
mass of component = 1.20g mass of solution
molar mass of NaOH + molar mass of HCl = 40 + 36.5
= 76.5
substituting the value in the equation,
mass percentage = 1.20 / 76.5
= 37.5%
Therefore, percentage purity of the sodium hydroxide will be 37.5%.option A is correct.
Learn more about mass percentage,here here:https://brainly.com/question/14848802
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