Chemical burning and the sun...?

Question

I am having trouble with this problem. Estimate how long the Sun would last if it was just a huge fire that was releasing chemical energy. Assume that the sun begins with roughly 10^8 joules per kilogram, a chemical energy content typical of atomic matter. Show some work if possible...THANKS!

Answer 1

The sun is largely hydrogen & helium, with a bit of iron & other elements. The fraction of the sun that's oxygen, however, is minuscule, so you just wouldn't get any appreciable chemical burning. In order for your question to make any sense or to be possible at all, you'd need to state the chemical composition of the sun and say what percent is oxygen in your hypothetical question.

Answer 2

We are making some unrealistic assumptions here but...

You need to know the mass of the sun, m= 1.98892 × 10^30 and the power output of it: p = 4x10^26 watts

The unit of power is the watt. 1 watt = 1 joul/second

So, (mass of sun)*[10^8J/kg]*(1/power output of sun) = time it will take to burn out in seconds

Converting to years I get about 15756.699 years
Good thing the sun uses fusion.

Though, there may be some chemistry thing concerning redox reactions that I'm overlooking