Chemistry Class 11 NCERT Solutions: Chapter 1 Some Basic Concepts of Chemistry Part 11
Q: 33. Calculate the number of atoms in each of the following
Q: 34. A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives carbon dioxide, of water and no other products. A volume of (measured at STP) of this welding gas is found to weigh Calculate
(i) Empirical formula
(ii) Molar mass of the gas
(iii) Molecular formula
of water contains 2 g of hydrogen.
Since carbon and hydrogen are the only constituents of the compound, the total mass of the compound is:
Percent of H in the compound
Moles of carbon in the compound
Moles of hydrogen in the compound
= 1: 1
Hence, the empirical formula of the gas is CH.
Weight of of gas
Hence, the molar mass of the gas is
(iii) Empirical formula mass of