Question

Can I get some help balancing equations?


1. ____ H2 + ____ O2 --------> ____ H2O

2. ____ SeCl6 + ____ O2 --------> ____ SeO2 + ____ Cl2

3. ____ Mg + ____ Mn2O3 --------> ____ MgO + ____ Mn

4. ____ SiO2 + ____ HF --------> ____ SiF4 + ____ H2O

5. ____ C7H16 + _____ O2 -------> ____ CO2 + ____ H2O

6. Chemical equations are to chemists what _________ are to a chefs.

7. Explain the analogy in #6




8. ____ C2H6 + ____ O2 --------> ____ H2O + ____ CO2

Help, answers--anything helps. Thanks!

Answer 1

It might help if you made a chart counting the number of individual elements on each side. For example, number 5 (which is also known as a combustion reaction):
You have, on the reactant side (the left):
carbon = 7
hydrogen = 16
oxygen = 2
AND on the RIGHT side (product side):
carbon = 1
oxygen = 3
hydrogen = 2

To completely balance these equations, you are going to want to find a number which you can multiply to give you the same number of carbon, hydrogen, and oxygen on both sides! Remember that it follows the distributive property, so if you put a number 2 in front of heptane (C7H16) - as an example- you will now have:
carbon = 14 (because 2 x 7 = 14)
hydrogen = 32 (because 2 x 16 = 32)

So, if you follow everything correctly, you should get: \[C_7H_{16}+11O_2 \rightarrow 7CO_2 + 8H_2O\]
If you notice, you have 7 carbons, 16 hydrogen, and 22 oxygen on BOTH sides.

Answer 2

I'll help you on #7 also by giving you the numbers you want to get. You can figure out the numbers to total for each element on both sides:
carbon = 4
hydrogen = 12
oxygen = 14

Answer 3

So for number 2, would the balanced equation be this?
SeCl6 + O2 --------> SeO2 + 3 Cl2

Answer 4

That's correct
REACTANT SIDE:
Se = 1
Cl = 6
O = 2
PRODUCT SIDE:
Se = 1
O = 2
Cl = 6

Answer 5

Sweet! Thanks for the help. I actually understand it now.