OCR SUMMER 2026
PREDICTED PAPER
GCSE (9–1) Combined Science A
(Gateway Science) WORKED SOLUTIONS
J250/10 Chemistry ( Higher Tier)
Time allowed: 1 hour 10 minutes
You must have:
• a ruler (cm/mm)
• the Data Sheet for GCSE (9–1) Combined Science
A (Chemistry) (inside this document)
You can use:
a scientific or graphical calculator
• an HB pencil
H
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 60.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 16 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
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, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1.A student tests an unknown gas using damp blue litmus paper. The litmus paper turns white.
Which gas is present?
A Oxygen
B Hydrogen
C Chlorine
D Carbon dioxide
Your answer [1]
2.Which statement correctly describes the trend in reactivity of Group 7 halogens?
A Reactivity increases going down the group as atoms get larger
B Reactivity decreases going down the group as the outer shell gets further from the nucleus
C Reactivity stays the same as all halogens have 7 outer electrons
D Reactivity increases going down the group as more electrons are present
Your answer [1]
3.A student measures the rate of reaction between magnesium and hydrochloric acid by
collecting the hydrogen gas produced. Which of the following correctly describes the units of
rate of reaction when measuring gas volume?
A g s⁻¹
B cm³ s⁻¹
C mol s⁻¹
D dm s⁻¹
Your answer [1]
for more: tyrionpapers.com
, 3
4.According to collision theory, which statement best explains why increasing temperature
increases the rate of reaction?
A There are more reactant particles present in the same volume
B The activation energy of the reaction is permanently lowered
C Particles move faster and collide more frequently with energy exceeding the activation
energy
D The surface area of solid reactants increases
Your answer [1]
5. The following reversible reaction is at dynamic equilibrium in a closed system:
2SO₂(g) + O₂(g) ⇌ 2SO₃(g) (forward reaction is exothermic)
What happens to the position of equilibrium when the temperature is increased?
A Shifts right, producing more SO₃
B Shifts left, producing more SO₂ and O₂
C No change, as both sides contain gases
D Shifts right, as more energy is available
Your answer [1]
6. A student uses the disappearing cross method to investigate the reaction between sodium
thiosulfate and hydrochloric acid. Which of the following is a disadvantage of this method
compared to collecting gas in a syringe?
A It cannot measure the rate of precipitation reactions
B The result is subjective and only one data point is produced per experiment
C Cotton wool must be used to prevent ejection of materials
D The units of rate cannot be calculated using this method
Your answer [1]
for more: tyrionpapers.com
PREDICTED PAPER
GCSE (9–1) Combined Science A
(Gateway Science) WORKED SOLUTIONS
J250/10 Chemistry ( Higher Tier)
Time allowed: 1 hour 10 minutes
You must have:
• a ruler (cm/mm)
• the Data Sheet for GCSE (9–1) Combined Science
A (Chemistry) (inside this document)
You can use:
a scientific or graphical calculator
• an HB pencil
H
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 60.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 16 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
for more: tyrionpapers.com
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1.A student tests an unknown gas using damp blue litmus paper. The litmus paper turns white.
Which gas is present?
A Oxygen
B Hydrogen
C Chlorine
D Carbon dioxide
Your answer [1]
2.Which statement correctly describes the trend in reactivity of Group 7 halogens?
A Reactivity increases going down the group as atoms get larger
B Reactivity decreases going down the group as the outer shell gets further from the nucleus
C Reactivity stays the same as all halogens have 7 outer electrons
D Reactivity increases going down the group as more electrons are present
Your answer [1]
3.A student measures the rate of reaction between magnesium and hydrochloric acid by
collecting the hydrogen gas produced. Which of the following correctly describes the units of
rate of reaction when measuring gas volume?
A g s⁻¹
B cm³ s⁻¹
C mol s⁻¹
D dm s⁻¹
Your answer [1]
for more: tyrionpapers.com
, 3
4.According to collision theory, which statement best explains why increasing temperature
increases the rate of reaction?
A There are more reactant particles present in the same volume
B The activation energy of the reaction is permanently lowered
C Particles move faster and collide more frequently with energy exceeding the activation
energy
D The surface area of solid reactants increases
Your answer [1]
5. The following reversible reaction is at dynamic equilibrium in a closed system:
2SO₂(g) + O₂(g) ⇌ 2SO₃(g) (forward reaction is exothermic)
What happens to the position of equilibrium when the temperature is increased?
A Shifts right, producing more SO₃
B Shifts left, producing more SO₂ and O₂
C No change, as both sides contain gases
D Shifts right, as more energy is available
Your answer [1]
6. A student uses the disappearing cross method to investigate the reaction between sodium
thiosulfate and hydrochloric acid. Which of the following is a disadvantage of this method
compared to collecting gas in a syringe?
A It cannot measure the rate of precipitation reactions
B The result is subjective and only one data point is produced per experiment
C Cotton wool must be used to prevent ejection of materials
D The units of rate cannot be calculated using this method
Your answer [1]
for more: tyrionpapers.com
