Activity A moles need hlp

I would always start by balancing your carbons, and then balancing the rest from there.

1. C2H5OH + O2 —> CO2 + H2O - You have two carbons on the left and one on the right. Multiply CO2 by 2.
C2H5OH + O2 —> 2CO2 + H2O

Now balance hydrogen. You have 6 on the left and 2 on the right. Multiply H2O by 3.
C2H5OH + O2 —> 2CO2 + 3H2O

Now balance oxygen. You have 3 on the left and 7 on the right. You need 4 more on the left. Don’t multiply the C2H5OH by anything because that will change the numbers of everything else too. Multiply O2 by 3 instead.
C2H5OH + 3O2 —> 2CO2 + 3H2O

Check that all atoms are now balanced, and you’re good.

2. Same process as before.

First carbons - C3H8 + O2 —> 3CO2 + H2O
Then hydrogens - C3H8 + O2 —> 3CO2 + 4H2O
Then oxygens - C3H8 + 5O2 —> 3CO2 + 4H2O

3. Same again.

Carbons) C6H12O6 + O2 —> 6CO2 + H2O
Hydrogens) C6H12O6 + O2 —> 6CO2 + 6H2O
Oxygens) C6H12O6 + 6O2 —> 6CO2 + 6H2O

4. The general reaction for a combustion reaction is a hydrocarbon reacting with oxygen to produce carbon dioxide and water.

Determine the  wavelength of light emitted when an electron  in an li2+ ion  makes a transition from an orbital with n  =  6 to an orbital with n  = 5.