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Draw a dot and cross diagram of a Chlorine molecule showing the outer electrons only.

Chlorine has seven outer electrons. Electrons like to be in pairs. In one Chlorine atom, there are three pairs and one lonely electron which doesn't have a pair. (draw). So two Chlorine atoms form a Chlorine...
LM
Answered by Lisa M. • Chemistry tutor
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Write a word equation for the reaction between marble chips and hydrochloric acid. (1) How could the rate of reaction be increased and why? (7)

i) Marble chips are made from calcium carbonate.Hydrochloric acid + calcium carbonate -> Calcium chloride + water + carbon dioxideii) The rate of reaction can be increased by increasing the concentration ...
MK
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Calculate the percentage of Copper in Copper oxide (CuO, Mr=80). (3 marks)

Ar of Cu = 64 (1 mark) Percentage of copper in CuO = 64/80 x100 (1 Mark) Percentage of copper in CuO = 80% (1 mark)
KD
Answered by Katie D. • Chemistry tutor
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Propane burns completely to produce carbon dioxide and water. Describe how you would use limewater to show that carbon dioxide is produced.

If carbon dioxide is present, when the solution produced is mixed with lime water if it turns cloudy this will prove that carbon dioxide is present.
HA
Answered by Huzair A. • Chemistry tutor
3572 Views

Define a hydrocarbon and explain the difference between alkenes and alkanes.

A Hydrocarbon is an organic molecule containing only hydrogen and carbon atoms. Alkanes are saturated hydrocarbons, meaning they are only made up of single bonds. The carbons are 'saturated' with hydrogen at...
SH
Answered by Saskia H. • Chemistry tutor
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