Quantitative Chemistry | AQA GCSE Combined Science Trilogy Chemistry, Higher tier (8464)
Quantitative Chemistry
- 101 questions
- 6 subtopics
- Chemistry Paper 1
- Chemistry Paper 1
Quantitative Chemistry is examined in Chemistry Paper 1.
It covers conservation of mass and balanced chemical equations, relative formula mass and concentration of solutions, mass changes when a gas is involved, and measurement uncertainty, moles, amounts of substances in equations, and balancing using moles and limiting reactants.
Sample questions from Quantitative Chemistry
Answer each one closed book first, then open the answer.
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Conservation of mass and balanced chemical equations
Explain why chemical reactions can be represented by balanced symbol equations.
Show the answer
Because no atoms are lost or made, the number of atoms of each element must be the same on both sides of the equation. -
Conservation of mass and balanced chemical equations
What is the difference between a number written in normal script in front of a formula and a number written in subscript inside a formula?
Show the answer
A number in front multiplies the whole formula that follows it, while a subscript multiplies only the atom or bracketed group it comes after. -
Relative formula mass and concentration of solutions
How is the percentage by mass of an element in a compound calculated?
Show the answer
Divide the total relative atomic mass of that element in the formula by the relative formula mass of the compound, then multiply by 100. -
Relative formula mass and concentration of solutions
12 g of a solid is dissolved and the solution made up to 0.5 dm³. What is its concentration in g/dm³?
Show the answer
24 g/dm³. -
Mass changes when a gas is involved, and measurement uncertainty
What is always true about the result of any measurement that is made?
Show the answer
There is always some uncertainty in the value obtained. -
Mass changes when a gas is involved, and measurement uncertainty
What is an anomalous result?
Show the answer
A result that does not fit the pattern shown by the rest of the data. -
Moles
How does the number of particles in one mole of one substance compare with the number in one mole of any other substance?
Show the answer
It is the same number of the stated particles in both. -
Moles
How does the number of atoms in one mole of carbon compare with the number of molecules in one mole of carbon dioxide?
Show the answer
The two numbers are the same.
The 6 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Conservation of mass and balanced chemical equations | The law of conservation of mass, calculating masses in sealed reactions, why reactions are shown by balanced equations, balancing the equations for hydrogen and methane burning, the difference between balancing numbers and subscripts, and counting atoms in formulae such as 3H₂SO₄ and 2Ca(OH)₂. | 12 |
| Relative formula mass and concentration of solutions | Defining and calculating relative formula mass, showing both sides of a balanced equation total the same, percentage by mass of an element, and concentration in g/dm³ from the mass of solute and the volume of solution. | 16 |
| Mass changes when a gas is involved, and measurement uncertainty | Why a metal gains mass when heated in air and a carbonate loses mass when decomposed, apparent breaches of conservation of mass explained with particles, the effect of sealing the container, uncertainty from the range of repeats, accuracy, precision, repeatability and reproducibility, random and systematic errors, anomalous results, resolution and reading scales, and mean, median and mode. | 32 |
| Moles | The mole as the unit of chemical amount, why it is used, the mass of one mole from relative formula mass, the Avogadro constant, and converting between mass and moles. | 15 |
| Amounts of substances in equations, and balancing using moles | The steps of a reacting mass calculation, mole ratios from balancing numbers, worked masses for magnesium oxide, carbon dioxide and ammonia, deducing a balanced equation from reacting masses, and rearranging the moles formula. | 15 |
| Limiting reactants | What the limiting reactant is, why one reactant is used in excess and what happens to it, which reactant fixes the mass of product, and worked examples with magnesium, oxygen, acid and ammonia. | 11 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
AQA GCSE Combined Science Trilogy Chemistry, Higher tier Active Recall Guide
Every topic, not just this one. 1,222 questions with their answers.