WorksheetsChemical reactions Grade 8
Total questions: 20
Worksheet time: 4mins
The substances taking part in a chemical reaction are called (a)
Substances formed after chemical reaction are called (a)
The formation of gas bubbles in a liquid during a chemical reaction is called (a)
When an iron nail is kept in copper sulphate solution, the solution turns (a) in colour.
Pb(NO3)2 when heated forms _______+ _______+ ______
(write the answer in words)
(a)
A substance that increases or decreases the rate of a reaction without participating in the reaction is called (a)
Substances that improve the efficiency of a catalyst are called (a)
CaCO3 when heated gives CaO and CO2
This reaction is an example of _______ reaction.
combination
dissociation
decomposition
neutraization
Mg reacts with O2, MgO is formed. This reaction is an example of (a) reaction.
Neutralization reaction is a type of ________ reaction.
displacement
double displacement
combination
decomposition
In a neutralization reaction, _____ and ______ are formed.
(a)
All metallic oxides and metallic hydroxides are called ______
Acids
Bases
Precipitates
None of the above
The most reactive metal is (a)
Bee sting contains ______ acid.
hydrochloric
nitrous
acetic
formic
Phenolphthalein turns ______ in an acidic solution.
Pink
blue
Colourless
yellow
True or false:
Hydrogen is more reactive than copper.
(a)
A chemical reaction in which heat is absorbed is called ________ reaction.
endothermic
exothermic
neutralization
decomposition
Metallic hydroxides that dissolve in water are called _____
acids
bases
alkalis
none of the above
True or false
Quick lime is acidic in nature.
(a)
ZnO is an example of _________ oxide.
basic
acidic
neutral
amphoteric
