Combined Chemistry questions to take note of for O level examination. (Compiled from school notes, past year papers, personal questions and other books)
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Erstellt von kaylynntanner
vor etwa 9 Jahre
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Erstellt von kaylynntanner
vor etwa 9 Jahre
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What is the main element in charcoal and how does it aid in changing carbon dioxide to carbon monoxide?
What is marble composed of?
Are limestone, lime and limewater composed of the same substances?
What gas is liberated from the reaction between marble and hydrochloric acid?
What is the difference between a burette and a pipette?
What property of a soluble solid allows it to be crystallised out from its solution?
Give an example of a solid mixture that can be separated by this procedure:
-adding distilled water to the mixture
-filtering the solution
-allowing the filtrate to evaporate and crystallise
How can you use dilute sulfuric acid to remove sulfur from a iron-sulfur (powder) mixture?
(sulfur and iron are insoluble in water. sulfur does not react with acids while iron reacts with acids.)
Suggest a method to obtain iron powder from a iron-sulfur mixture (powder).
Give 2 mixtures that can be separated by filtration.
Filtration is used in the treatment of river water to obtain drinking water. The river water is filtered using layers of sand, gravel and pebbles. What is the reason for using the layers of sand, gravel and pebbles?
Seawater is filtered using a filter funnel fitted with a piece of filter paper. The filtrate obtained is salty. Why is this so?
1g of water and 1g of steam contain the same number of molecules. Explain why the volume of steam is much greater than that of water.
