An element 7A14 exists as diatomic gas in nature which is relatively inert and forms 78% of earth’s atmosphere.
An element 7A14 exists as diatomic gas in nature which is relatively inert and forms 78% of earth’s atmosphere.
(a) Identify the gas and write its molecular formula. Write the formulae of its nitrite and nitrate ions.
(b) How many moles of this gas would contain 12.044 × 1023atoms of this element? (Avogadro’s no. = 6.022 × 1023)
(c) Calculate the molecular mass of
(i) NH4 NO3 and (ii) HNO3
(Given atomic masses N = 14 u, O = 16 u, H = 1u)
1 Answers
(a) Element A has atomic number 7 so it is Nitrogen gas (N2)
Formulae: Nitrite ion (No2 −)
Nitrate ion (No3 −)
(b) 1 mole of N2 gas = 6.022 × 1023 molecules of N2
= 12.044 × 1023 atoms of N
(c) (i) Molecular mass of NH4 NO3
= 14 + 1 × 4 + 14 + 3 × 16
= 80 u
(ii) Molecular mass of HNO3
= 1 + 14 + 3 × 16
= 63 u