A chemist prepares a solution of calcium bromide (CaBr2) by. measuring out 25. μmol of calcium bromide into a 50. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in μmol/L of the chemist's calcium bromide solution. Be sure your answer has the correct number of significant digits.

1.89 Imagine that you place a cork measuring 1.30cm4.50cm3.00cm in a pan of water. On top of this cork, you place a small cube of lead measuring 1.15 cm on a side. Describe how you would determine if the combination of the cork and lead cube will still float in the water. Note any information you would need to look up to answer the question.

Suppose that you are closing a cabin in the north woods for the winter and you do not want the water in the toilet tank to freeze. You know that the temperature might get as low as 30. C, and you want to protect about 4.0 L water in the toilet tank from freezing. Calculate the volume of ethylene glycol (density = 1.113 g/mL; molar mass = 62.1 g/mol) you should add to the 4.0 L water.

Specific gravity is a physical property. Beakers hold three clear, colorless liquids A, B, and C. The values of the specific gravities of the liquids are measured and then listed in the Before freezing column. The beakers are placed in a freezer until a solid crust forms across the surface of each. The beakers are placed in a freezer until a solid crust forms across the surface of each. The crusts are removed, and the liquids are warmed to room temperature. Their specific gravities are measured again, and then their values are listed in the After Freezing column. Which beakers contains a pure substance, and which contain a mixture? Explain your reasoning

The photograph below shows a beaker of water and a sugar cube, the combined mass of which is balanced by the weights on the right pan. The sugar cube is then placed in the water, and it dissolves completely. Do weights need to be added to or taken away from the right pan to keep the system in balance? Explain.

To determine the average mass of a popcorn kernel, you collect the following data: Plot the data with number of kernels on the x-axis and mass on the y-axis. Draw the best straight line using the points on the graph (or do a least- squares or linear regression analysis using a computer program), and then write the equation for the resulting straight line. What is the slope of the line? What does the slope of the line signify about the mass of a popcorn kernel? What is the mass of 20 popcorn kernels? How many kernels are there in a handful of popcorn with a mass of 20.88 g?

What phases or states of matter are present in a glass of bubbling carbonated beverage that contains ice cubes?

Please put the right amount of significant figures

A chemist prepares a solution of barium chloride BaCl2 by measuring out 44.0μmol of barium chloride into a 150.mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in /molL  of the chemist's barium chloride solution. Round your answer to  3  significant digits.

A chemist prepares a solution of barium chlorate (Ba(C10;),) by measuring out 119. umol of barium chlorate into a 350. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mmol/L of the chemist's barium chlorate solution. Round your answer to 3 significant digits. mmol ?