Which equation below represents deposition?
2Al(s) + 3Br2(g) → 2AlBr3(s)
MgCO3(s) + 2HCl(aq) → MgCl2(aq) + CO2(g) + H2O(l)
I2(g) → I2(s)
HgCl2(s) → HgCl2(g)
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Syllabus Edition
First teaching 2023
First exams 2025
Which equation below represents deposition?
2Al(s) + 3Br2(g) → 2AlBr3(s)
MgCO3(s) + 2HCl(aq) → MgCl2(aq) + CO2(g) + H2O(l)
I2(g) → I2(s)
HgCl2(s) → HgCl2(g)
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Below are three statements about mixtures. Which of them are correct?
I Mixtures can contain elements and compounds.
II The components of a mixture must be in the same state.
III The components of a mixture keep their own properties.
I and II only
I and III only
II and III only
I, II and III
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Which box shows a heterogeneous mixture?
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Name the six changes of state, and state which changes are accompanied by a decrease in particle separation distances.
State the difference between a homogeneous and a heterogeneous mixture.
Classify the following mixtures as homogeneous or heterogeneous: crude oil, concrete and brass.
Which technique would be the most suitable for the separation of crude oil?
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Which equation does not represent sublimation or deposition?
NH3 (g) + HCl (g) → NH4Cl (s)
I2 (s) → I2 (g)
C16H10O (s) → C16H10O (g)
H2O (g) → H2O (s)
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Which of the following is a heterogeneous mixture?
An aqueous solution of copper(II) chloride
An alloy of iron, carbon and chromium
A mixture of sulfur and potassium chloride
A mixture of ammonia, hydrogen sulfide and methane gases
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Which statement is correct about recrystallisation when purifying a solid?
The solid must be insoluble in the hot solvent
The impurities will remain in the solvent when cooled
The yield of product is the same after recrystallisation
The solvent is in excess during recrystallisation
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The correct combination relating to state change, particles and energy is:
A |
Subliming |
particles move further apart |
particles gain energy |
B |
Vaporizing |
particles come closer together |
particles gain energy |
C |
Melting |
particles move further apart |
particles lose energy |
D |
Condensing |
particles come closer together |
particles gain energy |
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Which of the following mixtures is NOT classified as homogeneous?
Salt solution
Brass
Orange juice that has been filtered
Concrete
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The order in which oxygen, methane, nitrogen and argon will diffuse from slowest to fastest, at the same conditions of temperature and pressure is:
O2 ﹤ N2 ﹤ Ar ﹤ CH4
CH4 ﹤ Ar ﹤ N2 ﹤ O2
N2 ﹤ O2 ﹤ Ar ﹤ CH4
Ar ﹤ O2 ﹤ N2 ﹤ CH4
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Chlorofluorocarbons have been used extensively as liquid coolants in refrigerators and air conditioners. Which of the following descriptions explains how a refrigerant works?
At high pressure the liquid evaporates and absorbs heat, cooling the surroundings
At low pressure the liquid evaporates and absorbs heat, cooling the surroundings
At high pressure the liquid condenses and absorbs heat, cooling the surroundings
At low pressure the liquid condenses and absorbs heat, cooling the surrounding
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