The percentage of water in human body is:
80%
70%
60%
50%
Water is an extremely stable:
atom
element
mixture
compound
Impurities in water:
Lower the freezing point
increase the boiling point
none of these
both of these
Our body temperature is maintained at:
20oC
41oC
37oC
11oC
Metals react with water to form:
oxides and hydroxides
oxides and chlorides
hydroxides and carbonates
oxides and sulphides
Water produces hydrogen and oxygen in the ratio of:
1 : 1
2 : 1
1 : 2
2 : 3
When water is cooled it contracts until it reaches ______ and then it starts expanding.
40oC
0oC
4oC
To lower the freezing point of water _______ is added.
sand
salt
sugar
sawdust
Which of the following is a balanced equation?
H2 + 2O2 → 2H2O
2H2 + O2 → H2O
H2 + O2 → H2O
2H2 + O2 → 2H2O
The process of breaking down of a compound of passing electric current through it is called:
hydrolysis
photosynthesis
electrolysis
distillation
