Question

Based on the relationships between molecular weight, moles, and mass of the substance, how many moles are in 40.0 grams of water? molecular weight of water is equal to 18.1 g/mol. a) 2.21 moles b) 4.42 moles c) 3,45 moles d) 2.53 moles

Answer 1

Answer: 2.22 moles

Step-by-step explanation:

Molar mass

The molar mass of water, or H2O, can be found by adding the molar mass of two hydrogen atoms and the molar mass of one oxygen atom, which comes out to be 18.0 g/mol.

To find the moles in 40.0 grams of water, we will set up a proportion.

`(18.0 g)/(1 mol) =(40.0g)/(xmol) \\`

Then, we just solve for x.

`18=(40)/(x) \\x=(40)/(18) \\x=2.22 mol`

40.0 g of water is 2.22 moles.