Read the chemical equation shown. 2Ag + H2S → Ag2S + H2

Which statement is true about this chemical equation?

Ag (silver) is oxidized and H (hydrogen) is reduced.
Ag (silver) is reduced and H (hydrogen) is oxidized.
S (sulfur) is reduced and H (hydrogen) is oxidized.
S (sulfur) is oxidized and Ag (silver) is reduced.

An aqueous solution of hydroiodic acid is standardized by titration with a 0.186 m solution of calcium hydroxide. if 26.5 ml of base are required to neutralize 20.3 ml of the acid, what is the molarity of the hydroiodic acid solution? m hydroiodic acid

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.

Why is the melting of ice a physical change ?