Question

There are 1.806x10^25 molecules of water (H20). how many moles of water does the sample contain?

a: 30.0 moles
b: 90.0 moles
c: 1.08 x 10^48 moles
d: 6.02 x 10^24 moles

Answer 1

Answer : The number of moles of water sample contains are, 30.0 moles

Explanation : Given,

Given molecules of water =
`1.806* 10^(25)`

According to the mole concept,

As,
`6.022* 10^(23)` molecules of water present in 1 mole of water.

So,
`1.806* 10^(25)` molecules of water present in
`(1.806* 10^(25))/(6.022* 10^(23))=29.99\approx 30.0` mole of water.

Therefore, the number of moles of water sample contains are, 30.0 moles

Answer 2

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles. We calculate as follows:

1.806x10^25 molecules H2O ( 1 mol / 6.022 x 10^23 molecules ) = 29.99 mole H2O = 30 moles------> OPTION A