What is the coefficient for O2 when the following chemical equation is balanced?
___Si2H3 + ___O2 → ___SiO2 + H2O

Hey there!

Si₂H₃ + O₂ → SiO₂ + H₂O

Balance H.

3 on the left, 2 on the right. Add a coefficient of 2 in front of Si₂H₃ and a coefficient of 3 in front of H₂O.

2Si₂H₃ + O₂ → SiO₂ + 3H₂O

Balance Si.

4 on the left, 1 on the right. Add a coefficient of 4 in front of SiO₂.

2Si₂H₃ + O₂ → 4SiO₂ + 3H₂O

Balance O.

2 on the left, 11 on the right. We can't do this by simply adding coefficients to O₂ since 11 isn't divisible by 2. So we need to multiply the coefficients in front of everything else by 2 first.

4Si₂H₃ + O₂ → 8SiO₂ + 6H₂O

Now we can balance O properly.

2 on the left, 22 on the right. Add a coefficient of 11 in front of O₂.

4Si₂H₃ + 11O₂ → 8SiO₂ + 6H₂O

This is our final balanced equation:

4Si₂H₃ + 11O₂ → 8SiO₂ + 6H₂O  

This means the coefficient for O₂ when the chemical equation is balanced is 11.

Hope this helps!

i think its 100

i hope this !