A sample of hydrated calcium sulfate has a mass of 2.643 g. After dehydration, the sample has a mass of 2.090 g. What is the percent by mass of water in the hydrate?

2NBr3 + 3NaOH - N2 + 3NaBr + 3HBrO How many NaBr formula units are formed when 50 NBrz molecules and 57 NaOH formula units react? (Formula units are the equivalent of molecules for ionic compounds.)

Which product is made up of fatty acids that are derived from alkenes? margarine polystyrene cups pain relievers rubber tires

In a car cylinder, a piston moves up and down inside a cylinder, causing the substance inside to expand and contract. Which type of substance could be inside the cylinder? Gas only Liquid only Liquid or solid only Gas, liquid, or solid

At STP, what is the volume of 1.0 mole of carbon dioxide?

Which best describes the effect of J. J. Thomson's discovery?

A pycnometer weighs 25.60 g empty and 35.55 g when filled with water at 20°C. The density of water at 20°C is 0.9982 g/ml. When 10.20 g lead is placed in the pycnometer and the pycnometer is again filled with water at 20°C, the total mass is 44.83 g.

How does weathering affect the surface area of a rock? Explain your answer.

How would each of the following procedural errors affect the results to be expected in this experiment? Give your reasoning in each case. (A) Not all of the liquid was vaporized when the flask was removed from the water bath.

What volume of 2.00 m must be added to 150.0 ml of 1.00 m chloroacetic acid to produce a buffer solution having a ph of 3.30?

What is the mass (g) of 500. ml water if the density is 0.9901 g/ml?