How many moles are in 2.8 g of Mg?

Dwayne filled a small balloon with air at 298.5 k. he put the balloon into a bucket of water, and the water level in the bucket increased by 0.54 liter. if dwayne puts the balloon into a bucket of ice water at 273.15 k and waits for the air inside the balloon come to the same temperature, what will the volume of the balloon be? assume the pressure inside the balloon doesn’t change. type the correct answer in the box. express your answer to the correct number of significant figures. the volume of the balloon at 273.15 k is liters.

You have 125g of a certain seasoning and are told that it contains 76.0 g of salt what is the percentage of salt by mass in this seasoning

What does the mass of 0.7891 mol of ferric oxide (fe2o3)