1.If the number of molecules in a given sample of SO2 is 3.011 x10 ^{23}

Calculate the following:

a) Number of moles in the given sample

b) Mass of SO2 in the sample

c) Number of oxygen atoms in the sample

a).6.022 x 10

^{23}molecules of SO

_{2}= 1 mole of SO

_{2}

So, 3.011 x 10

^{23}molecules of SO

_{2}= (1/6.022 x 10

^{23}) x 3.011 x 10

^{23}mole of SO

_{2}

_{ }= 0.5 moles of SO

_{2}

b). 1 mole of SO

_{2}= 32 + 2 x 16 = 64 gm

So, 0.5 mole of sample of SO

_{2}= 64 x 0.5 = 32 gm

c). Mass of oxygen in 64 gm = (32 / 64) x100 = 50 %

hence, mass of oxygen atoms in given sample (32 gm) = 32 x 50/100 = 16 gm

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