Which reaction will distinguish between a primary and a secondary alcohol?
Warming with silver nitrate solution
Warming with acidified potassium dichromate(VI) solution
Dehydration, followed by reaction with Br2(aq)
Oxidation, followed by reaction with Fehling’s (or Tollens’) reagent
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A compound C has the following properties:
liquid at room temperature
soluble in water
reacts with aqueous sodium hydroxide
What could compound C be?
Propene
Propanol
Propanoic acid
Propyl propanoate
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A student adds a few drops of dilute nitric acid followed by a few drops of silver nitrate solution to a test tube containing an unknown colourless solution. A white precipitate is seen.
What ions could be present in the colourless solution?
Ammonium ions
Chloride ions
Sulfate ions
Magnesium ions
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A solution of ammonium sulfate is warmed in a test tube with a few drops of sodium hydroxide solution. A piece of damp red litmus paper is held near the mouth of the test tube.
Which of the following statements is true?
The litmus paper will turn blue
The litmus paper will remain red
The gas given off is sulfur dioxide
The gas given off is colourless and odourless
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An aqueous cation from Group 2 is first tested with sodium hydroxide solution and then with dilute sulfuric acid.
Test | Result |
Addition of sodium hydroxide | No reaction |
Addition of sulfuric acid | White precipitate |
Which cation could be present?
Magnesium
Barium
Calcium
Strontium
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Which of these anions produces a yellow precipitate when treated with acidified silver nitrate solution?
F-
C
Br
I-
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Some standard laboratory equipment is shown below
What reaction could this apparatus be used for?
Preparing a carboxylic acid
Cracking an alkane
Oxidising an alcohol
Halogenation of an alkene
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Some standard laboratory equipment is shown below, but the labels are missing.
The purpose of the part labelled X is
To check the boiling point of the reaction mixture
To separate the distillate from the reaction mixture
To check the purity of the distillate
To prevent gases from escaping
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Citronellol is a flavour molecule found in lemon grass, a popular ingredient in Asian cooking.
Which of the following tests would give a positive result with citronellol?
Addition of bromine water
Warm with Fehling’s solution
Warm with acidified potassium dichromate(VI) solution
Addition of bromine water
Warm with acidified potassium dichromate(VI) solution
Addition of bromine water
Warm with Fehling’s solution
Warm with Fehling’s solution
Warm with acidified potassium dichromate(VI) solution
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Ibuprofen is a common analgesic used to reduce fever, inflammation and pain. The chemical structure is shown below.
Which reagent could be used to identify a functional group in ibuprofen?
Sodium carbonate solution
Bromine water
Acidified potassium dichromate(VI) solution
Tollens’ reagent
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Samples of barium and calcium are added separately to beakers of cold water which contain a few drops of litmus solution.
Which observations will be made with the calcium and with the barium?
A gas is evolved
The solution turns blue
A white suspension appears in the water
The solution turns blue
A gas is evolved
A white suspension appears in the water
A gas is evolved
A white suspension appears in the water
The solution turns blue
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X is a Group II metal. It forms a hydroxide which is more soluble than calcium hydroxide. It forms a sulfate which is more soluble than barium sulfate.
strontium
strontium
beryllium
beryllium
magnesium
strontium
beryllium
magnesium
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What happens when a piece of strontium is placed in cold water?
bubbles of gas form slowly on the strontium
a vigorous effervescence occurs
the strontium floats on the surface of the water and reacts quickly
the strontium burns with a bright white flame, and a white solid is produced
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What happens when iodine is bubbled through aqueous potassium bromide?
iodine is oxidised to iodide ions
potassium bromide is reduced to bromine
no reaction occurs
bromide ions are oxidised to bromine
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A halogenoalkane is heated with aqueous sodium hydroxide and ethanol. The solution is then acidified with dilute nitric acid and silver nitrate solution is added. A cream coloured precipitate is seen.
Which halogenoalkane could be present?
CH3F
CH3
CH3Br
CH3
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Which reagent could detect the presence of butan-1-ol ?
Tollens’ reagent
Br2 (aq)
K2CrO7 (aq)
Fehling’s reagent
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Which statement is correct about recrystallisation in the preparation of an organic solid?
The organic solid must be insoluble in the hot solvent
The impurities remain dissolved in the solvent after cooling
The yield of the product is increased
The melting point of the solid is lowered after recrystallisation
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Lactic acid occurs naturally, for example in sour milk.
What is a property of lactic acid?
it decolourises aqueous bromine rapidly
it is insoluble in water
it reduces Fehling’s reagent
it reacts with sodium carbonate
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Three elements from Period 3 are reacted with oxygen and the resulting oxides are added to water and tested with universal indicator paper.
Which row shows the correct observations?
sodium forms a white solid sparingly soluble pH 8
magnesium forms a white solid dissolves in water pH 12
sulfur forms a steamy gas very soluble pH 2
sodium forms a white solid dissolves in water pH 12
magnesium forms a white solid sparingly soluble pH 8
sulfur forms a steamy gas very soluble pH 2
sodium forms a white solid dissolves in water pH 12
magnesium forms a white solid sparingly soluble pH 8
sulfur forms a yellow solid insoluble pH 7
sodium forms a white solid sparingly soluble pH 8
magnesium forms a white solid insoluble pH 7
sulfur forms a yellow solid insoluble pH 7
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Which of these anions forms a white precipitate when tested with acidified silver nitrate solution?
CO32-
SO42-
OH-
Cl-
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The apparatus below shows an organic synthesis reaction.
Which processes could be performed using the above apparatus?
Dehydration of C2H5OH
Oxidation of C2H5OH
Cracking of paraffin
Dehydration of C2H5OH
Oxidation of C2H5OH
Dehydration of C2H5OH
Cracking of paraffin
Dehydration of C2H5OH
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Oxaloacetic acid can be synthesised from fumaric acid in a two-step process involving the intermediate Z.
step 1 step 2
HO2CCH=CHCO2H → Z → HO2CCOCH2CO2H
fumaric acid oxaloacetic acid
Each step involved can be achieved in the laboratory by a single reagent.
What could be the intermediate Z and the reagent for step 2?
Z Reagent
HO2CCH(OH)CH2CO2H Fehling’s solution
Z Reagent
HO2CCH(OH)CH2CO2H warm acidified K2Cr2O7
Z Reagent
HO2CCHBrCH2CO2H warm acidified KMnO4
Z Reagent
HO2CCHBrCH(OH)CO2H warm NaOH(aq)
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Mohr’s salt is a green crystalline double salt containing three ions: two cations and one anion. One of the cations is iron(II).
Qualitative analysis of an aqueous solution of the salt gave the following results:
Test | Result |
Addition of H2SO4 (aq) | No change observed |
Addition of BaC | White precipitate |
Warm with NaOH(aq) | Pungent fishy smell |
The identity of Mohr’s salt could be:
NH4Fe(SO4)2.12H2O
(NH4)2Fe(SO4)2.6H2O
Fe(NH4)2(CO3)2
(NH4)2FeC4.2H2O
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Three chemical reagent bottles have lost their labels, but are thought to contain dilute sulfuric acid, sodium hydroxide solution and silver nitrate solution.
A student tests the three unknown solutions with solutions of barium chloride and magnesium nitrate and records any precipitates formed in a table.
| BaC | Mg(NO3)2 |
H2SO4 |
|
|
NaOH |
|
|
AgNO3 |
|
|
The number of white precipitates in this table will be
2
3
4
5
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Concentrated sulfuric acid is added in turn to three white inorganic salts, X, Y and Z.
The following observations were made:
Salt | Observations |
X | Black solid, steamy fumes, bad egg smell |
Y | Steamy colourless fumes and a white solid product |
Z | Steamy brown fumes and white solid product |
What are the identities of the white inorganic salts, X, Y and Z?
X Y Z
NaHSO4 Na2SO4 NaC
X Y Z
KI KBr KC
X Y Z
NaI NaC NaBr
X Y Z
NaBr NaI NaC
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The following apparatus can be used in the laboratory to prepare organic substances.
Which of the following reactions can be carried out using the apparatus shown?
C6H12O6 → C2H5OH
C3H7OH → C3H7Br
C3H6 → C3H7Br2
C3H7OH → C2H5COOH
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Cyclohexene can be prepared in the laboratory by distilling cyclohexanol with concentrated phosphoric acid.
The boiling points of water, cyclohexanol and cyclohexene are 100 oC, 162 oC and
83 oC respectively.
Which of the following statements is correct?
The concentrated phosphoric acid acts as an oxidising agent
Cyclohexanol is soluble in water
A separating funnel is needed to isolate the product
The distillate only contains organic liquids
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An organic compound, X, is tested with acidified potassium dichromate(VI) solution and Fehling’s solution and the result is recorded:
Test | Result |
Acidified potassium dichromate(VI) solution | Orange colour turns green |
Warm with Fehling’s solution | Blue colour turns to red precipitate |
From this information, which statement about X cannot be correct?
X could contain a primary alcohol, a secondary alcohol and an aldehyde
X could contain only an aldehyde
X could be glucose
X would give no result with Tollens’ reagent
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Cinnamaldehyde is a pale yellow, oily liquid that occurs in the bark of cinnamon trees and gives the spice its distinctive flavour.
Which of the following statements about cinnamaldehyde is correct?
When tested with Fehling’s solution, the organic product is C6H5CH=CHCOOH
When tested with Fehling’s solution, the organic product is C6H5CH=CHCH2OH
Addition of bromine water produces an E-isomer
When tested with acidified potassium dichromate(VI) the colour changes from green to orange
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The fractional distillation of a crude oil substitute can be carried out in the laboratory using the apparatus shown. A crude oil substitute is used as a safer alternative to crude oil which contains carcinogens.
Which of the following statements about the experiment is correct?
The apparatus should include a Liebig condenser
The apparatus has been clamped incorrectly and should be vertical
The distillate contains only alkanes
A 0 - 300 oC thermometer should be used in the experiment
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