#
calculate the number of particles in each of the following:

i) 46 grams of Na atoms (NUMBER FROM MASS)

ii) 8 grams of O_{2}molecules (NUMBER OF MOLECULE FROM MASS)

iii) 0.1 mole of carbon atoms (NUMBER OF GIVEN MOLES)

Therefore 1 Mole of Na = 23 grams = 6.023 X 10

^{23}atoms

46 grams of Na = 46/23 Moles

= 2 Moles

1 Mole = 6.023 X 10

^{23}atoms

2 Moles = 6.023 X 10

^{23}X 2

= 12.046 X 10

^{23}atoms

Therefore 46 grams of Na contains 12.046 X 10

^{23}atoms

2) Molecular Mass of O

_{2}= 16 + 16 = 32 U (O + O)

Therefore

1 Mole of O

_{2}= 32 grams

8 grams = 8/32 Moles

= 0.25 moles

= 0.25 X 6.023 X 10

^{23}atoms

= 1.50 X 10

^{23}atoms (Approximate)

Therefore 8 grams of O2 contain 1.50 X 10

^{23}atoms

3) 1 Mole of C = 12 grams = 6.023 X 10

^{23}atoms

0.1 Moles of C = 0.1 X 6.023 X 10

^{23}atoms

= 6.023 X 10

^{22}atoms

Therefore 0.1 moles of Carbon contain 6.023 X 10

^{22}atoms

**
**