Question
hers your 150 mt ot 250 ml beaker (with your partmer asing the usberi) ean eit nd rinse wih delonized (DD water. Label your beaket with your name. Clean our 10 ml piper, rinse it with DI wates, and thens rinse ie wish s smal (2 5 ml.) ortion of yout unknown solution. Pipet 10.00 ml. of your unknown solution to the clean beaker. Add about 25 mi. of DI water to the unknown sample are your 50 ml. besker on the balance, and add o.3-0.4 g of gramulased sinc ta . Then add the weighed zinc to the unknown sample. (You do not need to recond he zinc mass. You only need a quandiry in the correct mass range. as n excess of zinc to each sample. Smaller pieces of zinc result in a shotter reaction b. Specify the species from the net-ionic equation that is osidiaed and reduced Justify your answers, Species Oxidized Reason: Species Reduced Reason: Calculate the molarity of a solution that contains 20.275 g calcium bromide dissolved in 575 mL of solution. 3.
Explanation / Answer
3) Given,
mass of calcium bromide=CaBr2=20.275g
Volume of solution=575ml=575 ml*(1L/1000ml)=0.575L
moles of calcium bromide=mass of calcium bromide/molar mass of calcium bromide=20.275g/199.89 g/mol=0.101mol
Molarity of CaBr2,calcium bromide=mol/Volume=0.101 mol/0.575L=0.176 mol/L=0.176M
Molarity of CaBr2,calcium bromide=0.176M
