How many tons of carbon emissions are in a barrel of crude oil, a ton of coal, and 1000ft3 of natural gas?

Question

How many tons of carbon emissions are in a barrel of crude oil, a ton of coal, and 1000ft3 of natural gas?

Answer 1

0 emmissions. Unless you pour it out in your backyard and light it.

Answer 2

If you want to be exact you balance the chemical conversion equations of oxidizing these and multiply by the molar mass involved.

If you don't care, a multiplier of 3X the weight is close.  Convert the barrel to lbs, keeping in mind that the petro industry barrel is 42 gallons, not 55, and convert the NG keeping in mind you are dealing with a gas that has very low density.