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WorksheetsGrade 9 - Energy and Reactions
Total questions: 12
Worksheet time: 13mins
Many chemical reactions that cause explosion need ___________
carbon dioxide
oxygen
nitrogen
potassium
Explosive usually have _____________ to supply the oxygen needed.
oxidising agent
potasium nitrate
carbon dioxide
Which one of the following sentence is true for "oxidiser"?
releases oxygen
chemically mixing with oxygen
break bond with oxygen
Which one of the following oxidising agent is mixed with charcoal to make gunpowder?
sodium nitrate
calcium nitrate
potassium nitrate
What happens when heat is given to potassium nitrate?
it will explode
it will catch fire
it will release oxygen during thermal decomposition
How can we test that the released gas in potassium nitrate is oxygen?
through calcium hydroxide
lime water testing
by bringing a glowing splint near the gas
What steps needs to be taken to make the explosion react quicker?
release large amount of oxygen
break down the solid fuel into tiny pieces.
all the above
Which one of the following sentence is true about energy?
once energy is transferred, it is destroyed completely.
energy can only be transferred from solid to gas.
energy can be destroyed with high power lasers.
energy can neither be destroyed or created, it only gets transferred from one source to another.
What is the difference between exothermic and endothermic reaction?
Which one of the following is an example of endothermic reaction?
combustion
thermal decomposition
neutralisation
During a chemical reaction, the temperature changed from 18º C to 23º C? Which reaction took place?
exothermic
endothermic
Which one of the following reactions need continuous supply of energy?
combustion
neutralisation
thermal decomposition
