The starter and exit quiz of the lesson “Empirical formula calculations”, from the unit “Calculations involving masses” (Year 10 Science) by Oak National Academy.
Free to use. Edit it, share it and hand it out to your students.
Oak National Academy
12 questions
Which of the following is the correct formula for carbon dioxide?
Calculate the relative molecular mass (Mr) of carbon dioxide (CO₂).
If two molecules of hydrogen gas react with one molecule of oxygen gas, how many molecules of water are produced?
A reaction requires three molecules of nitrogen gas and nine molecules of hydrogen gas. What is the simplest ratio of nitrogen to hydrogen needed for this reaction?
If one unit of carbon dioxide has a mass of 44 grams, what would be the mass of two units of carbon dioxide?
If a compound is made of 30g of carbon and 70g of oxygen, what is the percentage by mass of carbon?
Which of the following best describes the term "empirical formula"?
Write the empirical formula for a compound with a molecular formula of C₆H₁₂O₆.
The empirical formula of a compound is NH₃ and its relative formula mass (Mr) is 34. What is its molecular formula?
True or false? Empirical formula shows the simplest ratio of how many atoms there are of each element in a substance. Molecular formula shows the exact numbers of atoms of each element.
Given 120g of carbon reacts with 10g of hydrogen to form a compound, calculate the simplest ratio of carbon:hydrogen in the compound. Use the relative atomic masses (Ar): carbon = 12, hydrogen = 1.
A compound is 85.7% carbon and 14.3% hydrogen by mass. Calculate its empirical formula. Use the relative atomic masses (Ar): carbon = 12, hydrogen = 1.
