Question

Design an experiment to collect data that supports the claim that a 1.0M NaCl solution is a homogenous mixture. Describe the steps using these pieces of equipment:

5 mL: Pipette
100mL: beaker mL
10 mL: graduated cylinder
50 mL: beakers
10 mL: pipette
Balance
Hotplate
100 mL of 1.0 M NaCl (ag)

Answer 1

Please Help me ASAP! I can't seem to figure it out

Answer 2

Do you have no clue whatsoever?

Answer 3

I have an idea, but my teacher wants us to write a professional procedure

Answer 4

I use the hot plate to separate the contents right? and then the balance to obtain the mass of Sodium?

Answer 5

Yes. If you add water and the NaCl solution into the beaker, and there is no sublimation going on after you heat it on the hot plate, you should be left with just the NaCl. You can then measure the mass.

Answer 6

Make sure that the NaCl is completely dry before you measure it.

Answer 7

So I use 100 mL beakers?

Answer 8

Also, how do i use the pipettes? to just measure out the 100 mL of 1.0M NaCl?

Answer 9

Please help me!!

Answer 10

pipettes are used to transfer a measured amount of liquid

Answer 11

Oh ok!
So how do I use the 50 mL beakers?

Answer 12

you know what a homogeneous mixture is right?

Answer 13

Ya, it contains compounds that are uniformly distributed

Answer 14

so to test that, you're going to have to take out a certain amount of the compound and check to make sure that the amount taken out is consistent with what the concentration of the homogeneous mixture was

Answer 15

Oh ok! Can you help me write the procedure?

Answer 16

Please? Thank you so much!

Answer 17

pipette X amount of NaCl into a beaker and fill with water. Pipette X amount of NaCl into another beaker and fill with water, or don't and just fill beaker full with NaCl solution.
Heat the beakers on the hotplate till you are left with just NaCl. Measure the mass of NaCl from each beaker and calculate if the mass matches the expected amount you originally pipetted out from the original solution of NaCl

Answer 18

So I have 100 mL of NaCl solution, so I put 50 mL into one beaker and 50 mL into another?

Answer 19

without the water?

Answer 20

yea, you can do it that way if you want.

Answer 21

but what I don't get is, why can't I just do all 100 mL in one beaker?

Answer 22

cause you want to know if your mixture is homogeneous or not. Extracting all the NaCl from one solution at once tells you nothing about whether it was uniformly mixed or not.

Answer 23

oh kk! also, how will the mass extracted be the same, if H20 evaporated?

Answer 24

wouldn't the mass be less after only NaCl was left?

Answer 25

you're only interested in the mass of NaCl, which is a solid at room temperature.

Answer 26

ya, but u said to make sure the mass left was the same amount i extracted with the pipette

Answer 27

When you extract with a pipette, you take out a certain amount of NaCl. If the mixture was homogeneous, you should be able to calculate how much NaCl (how many grams of it) you extracted with the pipette. If your calculation matches the amount of NaCl you weigh after evaporating it, then your mixture was homogeneous.

Answer 28

Ok thank you so much!!!

Answer 29

<3 You just saved my grade

Answer 30

lol. no problem