How would you prepare 100.0 mL of 0.400 M CaCl2 from a stock solution of 2.00 M CaCl2?

Measure 20mL of the stock

Explanation:

All we need to do is to find the volume of the stock solution needed. This is illustrated below:

C1 = 2M

V1 =?

C2 = 0.400 M

V2 = 100mL

C1V1 = C2V2

2 x V1 = 0.4 x 100

Divide both side by 2

V1 = ( 0.4 x 100) /2

V1 = 20mL

Therefore, to prepare the solution, we will measure 20mL of the stock solution and make it up to the 100mL mark.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.

b.false that your answer