Question

According to avogadro's law, 1 mole of
every substance occupies 22.4 Liters at NTP and contains avogadro's number ( 6.023 times 10^{23} ) of particles.
To calculate the moles, we use the
equation:
Number of moles ( =frac{text { Given mass }}{text { Molar mass }} ) Number of moles of ( mathrm{CaC}_{2}=frac{100 mathrm{g}}{64 mathrm{g} / mathrm{mol}}=1.56 mathrm{moles} )
[
mathrm{CaC}_{2}+2 mathrm{H}_{2} mathrm{O}(l) rightarrow mathrm{Ca}(mathrm{OH})_{2}(a q)+mathrm{C}_{2} mathrm{H}_{2}(mathrm{g})
]
According to stoichiometry,
1 mole of ( mathrm{CaC}_{2} ) gives ( 22.4 mathrm{L} ) of ( mathrm{C}_{2} mathrm{H}_{2} ) at NTP
1.56 moles of ( mathrm{CaC}_{2} ) gives ( =frac{22.4}{1} times 1.56=35 mathrm{L} )
of ( C_{2} H_{2} ) at NTP

# 7. The volume of gas at NTP produced by 100 gm of CaC, with water: CaC, + 2H2O + Ca(OH), +CH, (1) 70 litre (2) 35 litre (3) 17.5 litre (4) 22.4 litre

Solution