What is the percent by mass of 25.0 g of sodium acetate mixed with 40. g of water?

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

A5.000 g sample of niso4 h2o decomposed to give 2.755 g of anhydrous niso4. what is the formula of the hydrate? what is the full chemical name for the hydrate? what is the molar mass of the hydrate? niso4•_h2o what is the mass % of water in the hydrate?

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.