How many gold atoms are present in 4.0 x 10-10 mol of gold?

Evaluate this exponential expression,8. (2 + 3)2 – 42

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.

How many grams of mgbr2 are needed to produce 75g or metal?