Question detail

What is the number of moles in 50 g of water (H2O)?

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

2.78 mol

The relative formula mass of water (H2O) is 18 g/mol. Using the formula moles = mass / Mr, we find that 50 g / 18 g/mol = 2.78 mol.

Using Incorrect Ratios

Students often confuse the ratios of reactants and products in a balanced equation, applying mass ratios instead of mole ratios.

Always refer to the coefficients in the balanced equation to determine mole ratios, and remember that these ratios are not the same as mass ratios.

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