Your problem is based on a topic of chemistry known as stoichiometry.
You will need the atomic wt. Of H and O. They are respectively H=1 and O=16.
The calculations are as follows and are based on Avagodros number which gives us the number of molecules in 1 mole of any element:
A.)
1 mole=6.0223 X 1023 molecules of any element, therefore the calculation is 100 molecule x 1 mole/6.0223 X 1023 molcules /mole=1.06603 x 10-22 mole of water present in 100_g of H20
B.)
2H=1 and O=16, therefore 2H=2_g/mole and O=16_g/mole then add H and O for a ttl of 18_g/mole of water.
For the number of moles present in 100_g of water divide 100_g/16_g =6.25 moles of water present in 100_g of H2O
C.) This is very similar to A
150 molecules of O2 to moles is 150 molecules X 1 mole/6.0223 x 1023 molecules=2.4907 X 10-22 moles of O2 to five significant figures
I hope this answer's your questions, good luck.
You will need the atomic wt. Of H and O. They are respectively H=1 and O=16.
The calculations are as follows and are based on Avagodros number which gives us the number of molecules in 1 mole of any element:
A.)
1 mole=6.0223 X 1023 molecules of any element, therefore the calculation is 100 molecule x 1 mole/6.0223 X 1023 molcules /mole=1.06603 x 10-22 mole of water present in 100_g of H20
B.)
2H=1 and O=16, therefore 2H=2_g/mole and O=16_g/mole then add H and O for a ttl of 18_g/mole of water.
For the number of moles present in 100_g of water divide 100_g/16_g =6.25 moles of water present in 100_g of H2O
C.) This is very similar to A
150 molecules of O2 to moles is 150 molecules X 1 mole/6.0223 x 1023 molecules=2.4907 X 10-22 moles of O2 to five significant figures
I hope this answer's your questions, good luck.