Question

PLEASE HELP CAN'T FIGURE THIS OUT
1. For an experiment, a biology student makes 1 liter of a solution containing the following substances, which are shown in the table below. Using the given information, fill in the missing parts of the table for each substance by (a) providing the formula weight and (b) calculating either the mass the student needs to weigh out or the number of moles that the student has, based on the amount weighed out. For each calculation, show your work. Be sure to include the formula mass of water for CaCl2  2H2O and NaH2PO4  H2O.

Substance Formula Weight (g/mol) Number of Moles Mass (g)
NaCl 58.4 0.14
KCl 74 0.005
C6H12O6 1.01
NaHCO3 0.0262
CaCl2 x 2H2O 0.15
MgSO4 0.0008
NaH2PO4 x H2O 0.14

Answer 1

Number of moles * formula weight = mass

Answer 2

Do you know how to use the periodic table to calculate the formula weight of each compound?

Answer 3

Not really. Can you please help?

Answer 4

I'm really confused in this unit of chem..

Answer 5

To find formula weights, you find how many atoms of each element and multiply by that element's molar mass.

Answer 6

For instance, NaCl has 1 atom of sodium and 1 atom of chlorine. Thus, its formula weight is 1*22.9898+1*35.4527

Answer 7

Okay thanks. That helped a lot!

Answer 8

Sure thing. :) Let me know if you have any more trouble.

Answer 9

Will do. Thanks(: