154k views
5 votes
How many moles of water molecules, h2o, are present in a 27 gram sample of water?

User Molasses
by
8.5k points

2 Answers

4 votes
Molar mass of H2O = 1 x 2 (of 2 H) + 16 (of 1 O)
No. of moles of water = Mass/Molar mass = 27g/(18 g/mol) = 1.5 mol
User Bhanuday Birla
by
7.9k points
2 votes

Answer:

1.5 moles

Step-by-step explanation:

The formula to calculate number of moles (n) is

n = m/m.m where

m = mass (in gram)

m.m = molar mass (g/mol)

Mass of the water molecules has been given in the question to be 27 g

Atomic mass of hydrogen (H) = 1 g/mol

Atomic mass of oxygen (O) = 16 g/mol

Molar mass of water (H₂O) = (2 ₓ 1) + 16 = 18 g/mol

n = 27/18

n = 1.5 moles

1.5 moles of water molecules (H₂O) are present in 27 gram sample of water.

User Justin Bicknell
by
8.6k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.