Calculate :

(i) The number of moles in 12 g. of oxygen gas. [O = 16]

(ii) The weight of 10²² atoms of carbon.

[C = 12, Avogadro's No. = 6 x 10²³]

Calculate the volume occupied by 80 g. of carbon dioxide at s.t.p.

Fill in the blank from the choices given in bracket : The number of moles in 11 g. of nitrogen gas is …………… [0.39, 0.49, 0.29] [N = 14]

(i) State the volume occupied by 40 gm. of methane at stp if it's vapour density is 8.

(ii) Calculate the number of moles present in 160 g of NaOH.

[Na = 23, H = 1, O = 16]