PLEASE HELP ASAP Pls Answer the questions that are not answered.

In a laboratory, 1.55mg of an organic compound containing carbon, hydrogen, and oxygen is burned for analysis. this combustion resulted in the formation of 1.45mg of carbon dioxide and .89 mg of water. what is the empirical formula for this compound?

Which of the following changes will decrease the total amount of gaseous solute able to be dissolved in a liter of liquid water? (2 points) decreasing temperature decreasing pressure decreasing surface area decreasing solute concentration

The point along a planet's orbit where it is closest to the sun is called the