Question detail

How many moles are in 250 grams of sodium hydroxide (NaOH)? The relative formula mass (Mr) of NaOH is 40 g/mol.

Try the question, check the answer, then read the explanation to understand the curriculum point.

At a glance

MCQ

Type

practice

Style

Topic

Use of amount of substance in relation to masses of pure substances

Question

6.25 mol

The number of moles is calculated using the formula moles = mass / Mr. Here, moles = 250 g / 40 g/mol = 6.25 mol.

Decimal Misinterpretation

Students often misinterpret decimal values in mole calculations, treating them as whole numbers.

To fix this, practice converting decimal values into fractions or ensure proper decimal placement when calculating moles.

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