Question

Which solution could you prepare by dilution?

A. 400 milliliters of 2.50 molar solution from a 2.00 molar stock solution

B. 600 milliliters of 3.00 molar solution from a 2.50 molar stock solution

C. 700 milliliters of 4.50 molar solution from a 3.00 molar stock solution

D. 900 milliliters of 3.50 molar solution from a 4.50 molar stock solution

Please help me understand this question. :)

Answer 1

hint: when we dilute, the molarity of the prepared solution is lower than the molarity of the stock solution

Answer 2

so, look at each answer choice to see which one has a higher stock solution molarity than the prepared molarity

Answer 3

Ok

Answer 4

What's the difference between the molar solution and the molar stock solution? And how do you find the molarity?

Answer 5

That's where I get confused

Answer 6

molarity is given in the problem

Answer 7

ok, maybe I can explain it this way

the "stock solution" is a solution with a known concentration, and the "prepared solution" is a new solution that we make by taking part of the stock solution and adding water

Answer 8

Ohh ok

Answer 9

so, let's take a look at the first answer choice:

A. 400 milliliters of 2.50 molar solution from a 2.00 molar stock solution

this means, we take a 2.00 molar stock solution, and we try to make a new solution that is 400 ml and 2.50 molar

now, going by the rule I stated earlier, the stock solution molarity has to be higher than the new solution

2.00 molar stock is less than 2.50 molar solution so A cannot be our answer

Answer 10

keep going like this until you find the answer

Answer 11

Thank you so much for explaining :)