A student needs to prepare 100. mL of 0.618 M Cu(NO3)2 solution.  What mass, in grams, of copper(II) nitrate should the student use?  Enter a numerical value with the correct number of significant figures in the answer box.  Do not enter units, but know that the final units must be grams.

A chemistry student must write down in her lab notebook the concentration of a solution of sodium thiosulfate. The concentration of a solution equals the mass of what's dissolved divided by the total volume of the solution. Here's how the student prepared the solution: The label on the graduated cylinder says: empty weight: 6.250g She put some solid sodium thiosulfate into the graduated cylinder and weighed it. With the sodium thiosulfate added, the cylinder weighed 76.3 g. She added water to the graduated cylinder and dissolved the sodium thiosulfate completely. Then she read the total volume of the solution from the markings on the graduated cylinder. The total volume of the solution was 97.36 ml What concentration should the student write down in her lab notebook? Be sure your answer has the correct number of significant digits.

A titration is performed to determine the amount of sulfuric acid, H2SO4, in a 7.27 mL sample taken from car battery. About 50 mL of water is added to the sample, and then it is titrated with 39.67 mL of a standard 0.4862 molar NaOH solution. What is the molar concentration of sulfuric acid in the original sample? Give your answer in in decimal format. When entering units, use proper abbreviated units with proper capitalization.

Chlor-alkali plants electrolyze NaCl to produce the commodity chemicals caustic soda and chlorine gas.  Industrial waste effluent released into waterways from these plants can contain trace amounts of mercury.     Legally, the effluent can contain up to 2.50 x 10-9 mol/L of mercury.  Determine the minimum volume of water, in megalitres (ML), that must be added to a 1.14 g sample of mercury to dilute the effluent to acceptable levels.   Record only your numerical answer with the correct number of significant digits.  You do not need to include units as the units appear for you beside the answer box already.