Answer:
3.011 x 10^23 molecules
Step-by-step explanation:
- Mass of Sulphuric (H2SO4) = 49g
- We have the number of molecules in 49g of H2SO4
Molecular mass of H2SO4 = (Atomic mass of H) x 2 + (Atomic mass of S) x 1 + (Atomic mass of O) x 4
= ( 1 x 2) + (32 x 1) + (16 x 4)
= 2 + 32 + 64
= 98.
Now,
- According to the formula,
Number of moles in the given H2SO4(n) = Mass of H2SO4 in grams/Molecular mass of H2SO4
= 49/98
= 1/2
= 0.5
: n = 0.5 mol
- 1 mol of H2SO4 contains 6.022 x 10^23 molecules.
- 0.5 mol of H2SO4 contains 0.5 x 6.022 x 10^23 molecules.
= 3.011 x 10^23 molecules .
that is 49 g of H2SO4 contains 3.011 x 10^23 molecules of H2SO4.