Question

1 How many grams are there in 7.4 x 1023 molecules of AgNO3?

2 How many grams are there in 7.5 x 1023 molecules of H2SO4?
3 How many grams are there in 9.4 x 1025 molecules of H2?

PLZ HELP

Answer 1

In
`7,4.10^(23)` molecules of
`AgNO_3` are 209 g

In
`7,5.10^(23)` molecules of
`H_2SO_4` are 123 g

In
`9,4.10^(25)` molecules of
`H_2` are 312 g

Step-by-step explanation:

First remember that 1 mole of any element has
`6.02 10^(23)` molecules (this number is a constant).

we know that the molecular mass of an element relates the grams of that substance in 1 mol

To calculate how many grams of
`AgNO_3` are in
`7,4.10^(23)` molecules we use a rule of three

`6,02.10^(23) molecules \longrightarrow 1mol AgNO_3\\7,4.10^(23) molecules\longrightarrow x\\x=(7.,4.10^(23)molecules.1mol AgNO_3 )/(6,02.10^(23)molecules)\\x=1.23 mol AgNO_3`

The molecular mass of
`AgNO_3` is 169.87 g/mol

`1 mol \longrightarrow 169.87 g\\1.23 mol\longrightarrow x\\x=(1.23 mol. 169.87g)/(1 mol) \\x= 209 g AgNO_3`

In
`7,4.10^(23)` molecules of
`AgNO_3` are 209 g

To calculate how many grams of
`H_2SO_4` are in
`7,5.10^(23)` molecules we repeat the previous procedure

`6,02.10^(23) molecules \longrightarrow 1mol H_2SO_4\\7,5.10^(23) molecules\longrightarrow x\\x=(7.,5.10^(23)molecules.1mol AgNO_3 )/(6,02.10^(23) molecules)\\x=1.25 mol H_2SO_4`

The molecular mass of
`H_2SO_4` is 98.079 g/mol

`1 mol \longrightarrow 98.079g\\1.25 mol\longrightarrow x\\x=(1.25mol. 98.079g)/(1 mol)\\x= 123 g AgNO_3`

In
`7,5.10^(23)` molecules of
`H_2SO_4` are 123 g

To calculate how many grams of
`H_2` are in
`9,4.10^(25)` molecules we repeat the previous procedure

`6,02.10^(23) molecules \longrightarrow 1mol H_2\\9,4.10^(25) molecules\longrightarrow x\\x=(9,4.10^(25)molecules.1mol H_2)/(6,02.10^(23) molecules)\\x=156 mol H_2`

The molecular mass of
`H_2` is 2 g/mol

`1 mol \longrightarrow 2g\\156 mol\longrightarrow x \\x=(1.25mol. 98.079g)/(1 mol) \\x= 312g`

In
`9,4.10^(25)` molecules of
`H_2` are 312 g