31%
27%
21%
19%
Correct answer is C
Volume of O2 used = 200 - 158 = 42 cm3
% of O2 = (42)/(200) x 100% = 21%
Carbon is tetravalent because ...
The colour of phenolphthalein indicator in dilute HNO is ...
What is the atomic number of Einsteinium? ...
Which of the following is an electrolyte? ...
Biotechnology is applied in the following except ...
The sulphide that is commonly used in coating electric fluorescent tubes is? ...