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An experiment is set up as shown.
After several minutes, a white ring of ammonium chloride appears as shown.
Which statement explains the observation after several minutes?
A student put exactly 25.00 cm$^3$ of dilute hydrochloric acid into a conical flask. The student added 2.5 g of solid sodium carbonate and measured the change in temperature of the mixture. Which apparatus does the student need to use?
A student separates sugar from pieces of broken glass by dissolving the sugar in water and filtering off the broken glass.
What is the filtrate?
How many protons, neutrons and electrons are there in one atom of the isotope $^{27}_{13}Al$?
[Table_1]
Which description of brass is correct?
Some properties of diamond are shown.
1. It is very hard.
2. Every atom forms four bonds.
3. It does not conduct electricity.
Which properties are also shown by silicon(IV) oxide?
Which statement describes the attractive forces between molecules?
Which substance is described as a macromolecule?
The equation for the reaction of sodium with water is shown.
$$2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2$$
What is the volume of hydrogen gas, measured at r.t.p., produced when 18.4 g of sodium reacts with excess water?
Iron can be electroplated with zinc to make it resistant to corrosion.
Which row about electroplating iron with zinc is correct?
[Table_1]
Chlorine reacts with ethane to produce chloroethane and hydrogen chloride.
The reaction is exothermic. The bond energies are shown in the table.
[Table_1]
What is the energy change for the reaction?
Chlorine gas is bubbled into aqueous potassium iodide. What is the ionic equation for the reaction that takes place?
Concentrated aqueous sodium chloride is electrolysed.
Which equation represents the reaction at the cathode?
Which statements about hydrogen are correct?
1 When hydrogen is burned, heat energy is released.
2 When hydrogen is used in a fuel cell, electrical energy is generated.
3 When hydrogen is used as a fuel, water is the only product.
Solid X is heated strongly.
The colour of the solid changes from blue to white.
What is solid X?
Iron(II) chloride solution reacts with chlorine gas.
The equation is shown.
$2FeCl_2(aq) + Cl_2(g) \rightarrow 2FeCl_3(aq)$
Which statements about this reaction are correct?
1. $Fe^{2+}$ ions are reduced to $Fe^{3+}$ ions.
2. Chlorine acts as a reducing agent.
3. $Fe^{2+}$ ions each lose an electron.
4. $Cl_2$ molecules are reduced to $Cl^-$ ions.
Which statements about acids and bases are correct?
1. An acid reacts with a metal to give off hydrogen.
2. A base reacts with an ammonium salt to give off ammonia.
3. An acid reacts with a carbonate to give off carbon dioxide.
4. Alkaline solutions are orange in methyl orange.
Oxide 1 is a solid that reacts with dilute hydrochloric acid.
Oxide 2 is a gas that reacts with sodium hydroxide solution.
What are the formulae of the oxides? [Table_1]
Which reaction is a photochemical reaction?
The equation shown represents a reaction at equilibrium.
m and n represent the balancing numbers for the reactant and product respectively.
$$mP(g) \rightleftharpoons nQ(g)$$
A high temperature increases the concentration of Q.
A high pressure increases the concentration of Q.
Which statement about the reaction is correct?
A period of the Periodic Table is shown.
The letters are not their chemical symbols.
Which statement is correct?
All metal nitrates are soluble in water.
All metal chlorides are soluble except silver and lead.
All metal carbonates are insoluble except sodium and potassium.
Which aqueous solutions produce a precipitate when mixed together?
1. silver nitrate + sodium carbonate
2. silver nitrate + sodium chloride
3. barium nitrate + potassium chloride
Which row describes properties of transition elements?
[Table_1]
The noble gases are in Group VIII of the Periodic Table. Which statement explains why noble gases are unreactive?
Which statement is correct for all metals?
Carbon dioxide is produced during the extraction of aluminium from bauxite. Which statement describes how this carbon dioxide is made?
Aluminium objects do not need protection from corrosion.
Iron objects must be protected from corrosion.
Which statement explains why aluminium resists corrosion?
Which statements explain why zinc is used to protect iron from rusting?
1. Zinc is more reactive than iron.
2. Zinc is less reactive than iron.
3. Zinc can form alloys with iron.
4. Zinc acts as a sacrificial metal.
Which conditions are used in the Haber process? [Table_1]
Which process does not produce a greenhouse gas?
Which reaction involving sulfur dioxide is correct?
Lime (calcium oxide) is used to treat waste water from a factory.
Which substance is removed by the lime?
What is the structure of the ester formed from ethanoic acid and propanol?
Fuel X produces carbon dioxide and water when it is burned in air. So does fuel Y. What could X and Y be? [Table_1]
The structures of four organic molecules are shown. Which of the following represents an alcohol?
Which statement about ethene is correct?
Ethanol is manufactured by fermentation of sugars or by catalytic hydration of ethene. Which row states an advantage of each method? [Table_1]
Which statements about unsaturated hydrocarbons are correct?
1. They contain both single and double bonds.
2. They turn aqueous bromine from colourless to brown.
3. They can be manufactured by cracking.
Which polymers have the same linkage between monomer units?
The diagram shows the partial structure of Terylene. From which pair of compounds is it made?