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Inorganic and organic chemistry
10 ECAT Chemistry questions with answers and explanations.
Printable worksheet with answer key
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What is the shape of the SF6 molecule?
- 1 Square planar
- 2 Tetrahedral
- 3 Octahedral
- 4 Trigonal bipyramidal
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Correct answer: Octahedral
Sulphur has six bond pairs and no lone pairs, which gives an octahedral shape.
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Which catalyst is used in the Haber process for making ammonia?
- 1 Nickel
- 2 Vanadium pentoxide
- 3 Iron
- 4 Platinum
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Correct answer: Iron
Finely divided iron is the catalyst in the Haber process. Vanadium pentoxide is used in the Contact process.
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Which reagent distinguishes an aldehyde from a ketone?
- 1 Tollens' reagent
- 2 Bromine water
- 3 Litmus paper
- 4 Lime water
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Correct answer: Tollens' reagent
Aldehydes reduce Tollens' reagent to give a silver mirror. Ketones do not.
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According to Markovnikov's rule, the addition of HBr to propene gives mainly:
- 1 Propane
- 2 1-bromopropane
- 3 2-bromopropane
- 4 1,2-dibromopropane
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Correct answer: 2-bromopropane
The hydrogen goes to the carbon that already has more hydrogens, so bromine ends up on the middle carbon.
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Which type of alkyl halide reacts fastest by the SN1 mechanism?
- 1 Primary
- 2 Methyl
- 3 Tertiary
- 4 Secondary
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Correct answer: Tertiary
A tertiary carbocation is the most stable, so tertiary halides react fastest by SN1.
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What is the product when ethene reacts with steam in the presence of an acid catalyst?
- 1 Ethane
- 2 Ethanol
- 3 Ethanal
- 4 Ethanoic acid
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Correct answer: Ethanol
Acid-catalysed hydration of ethene adds water across the double bond to give ethanol.
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What is the hybridisation of sulphur in SF6?
- 1 sp3
- 2 sp2
- 3 sp3d
- 4 sp3d2
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Correct answer: sp3d2
Six bond pairs need six hybrid orbitals, which use one s, three p and two d orbitals.
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The general formula of the alkanes is:
- 1 CₙH₂ₙ₊₂
- 2 CₙHₙ
- 3 CₙH₂ₙ₋₂
- 4 CₙH₂ₙ
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Correct answer: CₙH₂ₙ₊₂
Alkanes are saturated hydrocarbons with this formula.
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Which of these is an alkene?
- 1 C₂H₄
- 2 CH₄
- 3 C₂H₆
- 4 C₂H₂
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The common name of sodium carbonate decahydrate is:
- 1 Baking soda
- 2 Table salt
- 3 Washing soda
- 4 Caustic soda