# chemistry

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I need help with a,b,and c. I tried to balance it but im having a little trouble

Ethane gas, C2H6, burns in air and produces carbon dioxide and water vapor.
a)write a balanced equation for this reaction.

I know this isnt balanced but is this what im working with? C2H6 + O ---> CO2 + H2O

b)If 15.0 liters of ethane sre burned at STP, how many liters of carbon dioxide are formed?

c)How many grams of water vapor are formed if 15.0 liters of ethane are burned?

C2H6 is ethane.
Oxygen is diatomic; i.e., O2, when in the uncombined state.
CO2 and H2O are correct. You also are correct that it isn't balanced. What do you need help with?

Ethane gas, C2H6, burns in air and produces carbon dioxide and water vapor.
a)write a balanced equation for this reaction.

I know this isnt balanced but is this what im working with? C2H6 + O ---> CO2 + H2O

2C2H6 + 7O2 ==> 4CO2 + 6H2O

b)If 15.0 liters of ethane sre burned at STP, how many liters of carbon dioxide are formed?

There is a long way and a short way of doing this. I will show you the long way because it will work ALL of this kind of problem; the short way works only if all of the reactants and products are gases.
Step 1. Write the balanced equation. You have that.

Step 2. Convert what you have into mols. You know that 1 mol of a gas occupies 22.4L at STP; therefore,
15.0L/22.4L = 0.6696 mols.

step 3. Using the coefficients in the balanced equation, convert what you have (in this case mols ethane) to mols of what you want (in this case) mols CO2.
mols CO2 = 0.6696 x (4 mols CO2/2 mols C2H6) = 0.6696 x 4/2 = 1.339 mols CO2. Note that the factor I used cancels the unit we don't want(ethane) and keeps the unit we want to convert to (CO2).

Step 4. Now convert mols of CO2 to Liters.
mols CO2 x 22.4L/mol = 1.339 mols x 22.4 = 30 liters CO2
Check my work. Check my arithmetic.

c)How many grams of water vapor are formed if 15.0 liters of ethane are burned?

Do this one the same way as part b except that in step 4, you want grams and not liters; therefore,
g H2O = mols H2O x molar mass H2O = ??