# ques no 24 may be 3 option and 25 may be 4 option with solution .

__Ques 24.__

So we know that 1 mole of any gas is equivalent to its molecular mass . - which in case of SO

_{2}= 32+16+16 = 64g

So, if 1 mole = 64g

then, 1.5 mole = 1.5*64 = 96g

Hence option(3)

and

__Ques 25__.

Molecular mass of sulphur trioxide = 32+16*3 = 32+48 = 80g

SO

_{3}- is a tetra atomic gas - that is as you can see there are 4 atoms existing in 1 SO

_{3}= 1 stom of S and 3 atoms of oxygen.

So 1 mole = 80g = will have 4*N

_{A}atoms.

Hence 20 g = 4*N

_{A}*20/80 = N

_{A}atoms = 6*10

^{23}atoms

Hence option (4)

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