molarity chemistry?

Question

1 Devise a measure of solute concentration that you would place on the label for the following case: You weigh out 2.56g of zinc iodide. you put the solid zinc iodied in a 500mL flask and fill the flask with water to the 500mL mark. you now have 500mL of a zinc iodide aqueous solution. on the label of the flask you write:


2. Two students need zinc iodide that is in solution in the following amounts;
student 1: 0.43g of zinc iodide
Student 2. 5.0x10^-4 moles of zinc iodide.
for each case use your 500mL of zinc iodide solution in exercise 1.

Answer 1

The molar mass of ZnI2: 319.18 g/mol.
Hence 2.56g zinc iodide = 0.00802 mol ZnI2
0.00802 mol /(500ml) = 0.0160 M
0.0160 M ZnI2 should appear on the label of the flask.

0.43g zinc iodide = 0.001347 mol ZnI2 = 84.0 ml of 0.0160 M ZnI2 .
5.0x10^-4 moles ZnI2 = 31.2 ml of 0.0160 M ZnI2

Answer 2

it truly is a stoichiometry downside , calculates dilution . you take advantage of the formula MOLARITY1XVOL1= MOLARITY2XVOL2 , with what's given .consistently employing equivalent products both area of equation , equivalent to ml to ml or L to L . for this reason 0.150M x (x)unknown ml vol = 0.00600 x 500 ml vol . answer = 0.00600x500 =3 , then 3/ 0.one hundred and fifty , bring about favor 20 ml .