Evidence of a chemical reaction includes anything that shows - A. a new substance has been formed
B. a solid has dissolved in a liquid
C. an interaction between two gases
D. a chance in the state of matter

The boiling point of propanoic acid is higher than that of 1-butanol because: propanoic acid has a higher molecular weight than 1-butanol. propanoic acid is more soluble in water than 1-butanol. propanoic acid is a better hydrogen bond donor than 1-butanol. propanoic acid forms hydrogen bonded dimers and 1-butanol does not. 1-butanol forms hydrogen bonded dimers and propanoic acid does not.

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

The empirical formula of a compound is ch2o and its mass is 120 amu/molecule, what is its formula?