Raunak took 5 moles of carbon atoms in a container and Krish also took 5
moles of sodium atoms in another container of same weight. (a) Whose
container is heavier? (b) Whose container has more number of atoms?
The difference in the mass of 100 moles each of sodium atoms and sodium
ions is 5.48002 g. Compute the mass of an electron.
You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without tasting?
Does the solubility of a substance change with temperature? Explain with the help of an example.
Give the chemical formulae for the following compounds and compute the
ratio by mass of the combining elements in each one of them. (You may
use appendix-III).
(a) Ammonia
(b) Carbon monoxide
(c) Hydrogen chloride
(d) Aluminium fluoride
(e) Magnesium sulphide
Which of the following symbols of elements are incorrect? Give their correct
symbols
(a) Cobalt CO
(b) Carbon c
(c) Aluminium AL
(d) Helium He
(e) Sodium So
Give the formulae of the compounds formed from the following sets of
elements
(a) Calcium and fluorine
(b) Hydrogen and sulphur
(c) Nitrogen and hydrogen
(d) Carbon and chlorine
(e) Sodium and oxygen
(f) Carbon and oxygen
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