Quantitative Chemistry | AQA GCSE Combined Science Trilogy Chemistry, Foundation tier (8464)

Quantitative Chemistry

58 questions
3 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 and mass changes when a gas is involved, and measurement uncertainty.

Sample questions from Quantitative Chemistry

Answer each one closed book first, then open the answer.

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

For 2H₂ + O₂ → 2H₂O, show that the totals of relative formula mass are the same on both sides, given H = 1 and O = 16.

Show the answer
The reactants total 2 × 2 + 32 = 36 and the products total 2 × 18 = 36, so both sides come to 36.
Relative formula mass and concentration of solutions

How is the concentration of a solution in g/dm³ calculated from the mass of solute and the volume of solution?

Show the answer
Divide the mass of solute in grams by the volume of the solution in cubic decimetres.
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.

The 3 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.	14
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

Quantitative Chemistry is 58 of the 1,039 questions in the guide.Get the guide, £7

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.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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.
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.