Question

how many molecules of H2SO4 are present if 5.2 grams of Oxygen are available

Answer 1

Molecular weight of H2SO4 reported is 98 g/mol

From there we know that: 2 g/mol are from H, 32 g/mol are from S, and 64 g/mol are from O.

So, in 98 g acid ----------> 64 g O

then x g acid <---------- 5.2 g O

x = 5.2 g O * 98 g acid / 64 g O = 7.9625 g acid

1 mol ---------> 6.02x10²³ molecules ....... and in 1 mol ---------> 98 g acid, then:

98 g acid ---------------> 6.02x10²³ molecules

7.9625 g acid --------------> Y

Y = 7.9625 * 6.02x10²³ / 98 = 4.89x10²² molecules of H2SO4.

Hope this helps