Question detail

If 10 g of magnesium oxide (MgO) is produced, how many moles of magnesium oxide are there?

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

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At a glance

MCQ

Type

practice

Style

Topic

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

Question

A. 0.125 mol
B. 0.25 mol
C. 0.5 mol
D. 0.75 mol

Answer

0.125 mol

Explanation

The relative formula mass of magnesium oxide (MgO) is 40.3 g/mol (Mg) + 16 g/mol (O) = 56.3 g/mol. The number of moles is 10 g / 56.3 g/mol = 0.125 mol.

Common mistake

Common Mistake in Substituting Values

Students often forget to include the correct units when substituting numerical values into equations, leading to incorrect answers.

Always ensure that you write the units next to each numerical value during substitution to maintain clarity and accuracy.

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