If 2.0 ml of water is added to 8.0 ml of a 0.30 m solution to make a new solution with a total volume of 10.0 ml, what is the concentration of the new solution?

To solve this we use the equation, 

M1V1 = M2V2

where M1 is the concentration of the stock solution, V1 is the volume of the stock solution, M2 is the concentration of the new solution and V2 is its volume.

0.30 x 8 = M2 x 10

M2 = 0.24 m of the solution

Hope this answers the question. Have a nice day.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.