Ordinary level 2025 North West regional mock chemistry guide
Ordinary level 2025 North West regional mock chemistry guide
b) i. Heat evolved when one mole of a substance is completely burnt in Oxygen (1)
ii. Mass of ethanol burnt = 35.56 – 34.56g (1) = 1g (1)
iii. 1g of ethanol release 29.7kJ/mol
therefore, 46g of ethanol will release 46 x 29.7/1 (1) = 1366.2kJ/mol(1)
c) I. Salt P is deliquescent (1)
Salt Q is hygroscopic (1)
ii. – Blue turns white (1)
-Water condenses at the cooler end of tube
– Salt becomes powder
– Crystal shape crumbles
Total = 10marks
4) a) but -2- ene(1)
b) i. Addition reaction(1)
ii. CH3CH2CHBrCH3(1)
iii. 2- bromobutane(1)
iv. Existence of two or more compounds with same molecular formula(1) but different structural
formulae.(1)
v. CH3CH2CH2CH2Br or CH3CH(CH3)CH2Br (1) for any
c) butane (1) or(cyclobutane) or 2methylpropane
Princess
April 20, 2025
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Ndji che Mohamed
June 3, 2025
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