Which of the following is an example of a chemical change?
a.
flour and sugar are sifted together into a measuring cup.

b.
a mixture of flour, sugar, eggs, and butter is baked to become a cake.

c.
the shell of an egg breaks when it is struck against a hard surface.

d.
chocolate squares are melted to make cake icing.

Which best describes how johannes kepler developed his laws of planetary motion

Explain why pure hydrogen cyanide does not conduct electricity, but become a conductor when it is dissolved in water? (at room temp, pure hcn exists as a volatile liquid)

Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. an industrial chemist studying this reaction fills a 25.0l tank with 4.5 mol of sulfur dioxide gas and 4.5 mol of oxygen gas at 30.°c. he then raises the temperature, and when the mixture has come to equilibrium measures the amount of sulfur trioxide gas to be 1.4 mol. calculate the concentration equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. round your answer to 2 significant digits.