Write “yes” or “no” below if the chemical equation is balanced or not.

1. 2H2 + O2 ---> 2H2O

2. S8 + 12O2 ---> 8SO3

3. HgO ---> Hg + O2

4. Zn + HCl ---> ZnCl2 + H2

5. 2Na + 2H2O ---> 2NaOH + H2

6. 2Al + 3FeO ---> Al2O3 + 3Fe

7. 4Si2H3 + 11O2 ---> 8SiO2 + 6H2O

8. Fe + O2 ---> Fe2O3

9. 2C7H6O2 + 15O2 ---> 14CO2 + 6H2O

10. 4FeS2 + 11O2 ---> 2Fe2O3 + 8SO2

11. Fe2O3 + H2 ---> Fe + H2O
12. 2K + 2Br2 ---> 2KBr
13. 2C2H2 + 5O2 ---> 4CO2 + 2H2O
14. 2H2O2 ---> 2H2O + O2
15. C7H16 + 11O2 ---> 7CO2 + 8H2O

My answers:

1.yes
2.yes
3.no
4.no
5.yes
6.yes
7.yes
8.no
9.yes
10.yes
11.no
12.yes
13.yes
14.yes
15.yes

Those look ok to me to let me put a bug in your ear. By typing your answers AT THE END we must scroll down the page to find the answer. Why not write the equation and write yes out to the right or just underneath. That way we can see immediately if all is ok without scrolling down the board. All of that takes time AND we may forget what was at the top or transpose answers and questions.

12 : is false everything else looks great

To determine if a chemical equation is balanced or not, you need to check if the number of atoms of each element is the same on both sides of the equation. Here's how you can check:

1. 2H2 + O2 ---> 2H2O
- Counting the atoms, we have:
4 Hydrogen atoms on the left and 4 Hydrogen atoms on the right.
2 Oxygen atoms on the left and 2 Oxygen atoms on the right.
- The equation is balanced. Answer: yes.

2. S8 + 12O2 ---> 8SO3
- Counting the atoms, we have:
8 Sulfur atoms on the left and 8 Sulfur atoms on the right.
24 Oxygen atoms on the left and 24 Oxygen atoms on the right.
- The equation is balanced. Answer: yes.

3. HgO ---> Hg + O2
- Counting the atoms, we have:
1 Mercury atom on the left and 1 Mercury atom on the right.
1 Oxygen atom on the left and 2 Oxygen atoms on the right.
- The equation is not balanced. Answer: no.

4. Zn + HCl ---> ZnCl2 + H2
- Counting the atoms, we have:
1 Zinc atom on the left and 1 Zinc atom on the right.
1 Chlorine atom on the left and 2 Chlorine atoms on the right.
1 Hydrogen atom on the left and 2 Hydrogen atoms on the right.
- The equation is not balanced. Answer: no.

5. 2Na + 2H2O ---> 2NaOH + H2
- Counting the atoms, we have:
2 Sodium atoms on the left and 2 Sodium atoms on the right.
4 Hydrogen atoms on the left and 4 Hydrogen atoms on the right.
2 Oxygen atoms on the left and 2 Oxygen atoms on the right.
- The equation is balanced. Answer: yes.

You can continue the process for the remaining equations to determine if they are balanced or not.