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A-1) Element X = Al ( aluminum)
Oxide of Al - Al2O3
Chloride of Al - AlCl3
A-9) Number of molecules in 0.25 moles of oxygen = 0.25 * 6.023*1023 = 1.505*1023 particles.
A-21) Out of NaOH, NaCl, Na 2 O, NaNO 3 , compound having polyatomic ion is NaNO 3 .
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