An unknown compound contains only carbon, hydrogen, and oxygen (CxHyOz). Combustion of 4.00 g of this compound produced 5.87 g of carbon dioxide and 2.40 g of water. How many moles of carbon, C, were in the original sample?
How many moles of hydrogen, H, were in the original sample?
(I would really like to know how to compute these values...)

Aballoon inflated with three breaths of air has a volume of 1.7 l. at the same temperature and pressure, what is the volume of the balloon if five more same-sized breaths are added to the balloon?

Modern weaponry has increased the number of deaths in wars and violent conflicts.

The yearly amounts of carbon emissions from cars in belgium are normally distributed with a mean of 13.9 gigagrams per year and a standard deviation of 5.8 gigagrams per year. find the probability that the amount of carbon emissions from cars in belgium for a randomly selected year are between 11.5 gigagrams and 14.0 gigagrams per year. a. 0.340 b. 0.660 c. 0.167 d. 0.397