GCSE CHEMISTRY - Quantitative Chemistry EXAM REVISION
QUESTIONS WITH VERIFIED SOLUTIONS LATEST 2025 UPDATE.
Define relative atomic mass. - ANSWER- The average mass of the atoms in an element
Define relative formula mass. - ANSWER- The sum of the relative atomic masses of all the
atoms shown in the formula.
What is a mole? - ANSWER- A measurement of the amount of a substance
What is Avogadro's constant? - ANSWER- 6.022 × 10²³
What is the formula for mass (g)? - ANSWER- Mr × moles
What is the conservation of mass? - ANSWER- In a reaction, the total mass of the reactants
must equal the total mass of the products.
What is thermal decomposition? - ANSWER- A reaction where heat causes a substance to break
down into simpler substances.
What is an excess? - ANSWER- When the amount of a reactant is greater than the amount that
can react.
What is a limiting reactant? - ANSWER- The reactant in a reaction that determines the amount
of products formed. Any other reagents are in excess and will not all react.
How do you calculate percentage yield? - ANSWER- (mass of product actually made ÷
maximum theoretical mass of product) × 100
QUESTIONS WITH VERIFIED SOLUTIONS LATEST 2025 UPDATE.
Define relative atomic mass. - ANSWER- The average mass of the atoms in an element
Define relative formula mass. - ANSWER- The sum of the relative atomic masses of all the
atoms shown in the formula.
What is a mole? - ANSWER- A measurement of the amount of a substance
What is Avogadro's constant? - ANSWER- 6.022 × 10²³
What is the formula for mass (g)? - ANSWER- Mr × moles
What is the conservation of mass? - ANSWER- In a reaction, the total mass of the reactants
must equal the total mass of the products.
What is thermal decomposition? - ANSWER- A reaction where heat causes a substance to break
down into simpler substances.
What is an excess? - ANSWER- When the amount of a reactant is greater than the amount that
can react.
What is a limiting reactant? - ANSWER- The reactant in a reaction that determines the amount
of products formed. Any other reagents are in excess and will not all react.
How do you calculate percentage yield? - ANSWER- (mass of product actually made ÷
maximum theoretical mass of product) × 100
