help!!!!!!!!!!!!?

Question

can anyone help with this?

as you are cleaning the kitchen cupboards, you come across four unlabelled jars, each containing clear, colourless liquids. You then find the four paper labels that must have fallen off the jars. The labels contain the following headings: water, rubbing alcohol, vingar, and salt water. Design an experiment that would allow you to determine the identity of each of the substances. Your experimental design should include:

+a detailed, coherent, and logical procedure
+a list of materials and exquipment
+a list of safety considerations, e.g., No tasting allowed!
+an observation chart
+three questions that would help you analyze your data in order to properly identify each substance
+a conclusion (or a statement about making connections or applications)

THANK YOU FOR YOUR TIME TAKING IN WRITING YOUR ANSWER!

Answer 1

To figure out which one the salt solution is, you could boil a small sample of each of the liquids and measure the boiling point. The salt solution should be around 100 C, a little above, but not too much due to the collegative property of boiling point elevation. Also, the salt solution is the one which should leave a salt behind when it does boil. To figure out which one is the vinegar, you can treat a small sample of each with a small amount of baking powder (sodium bicarbonate - a weak base). Since the active ingredient in vinegar is acetic acid it should react (giving off CO2) with the baking soda. If it reacts with two samples (there's a small possibility it would react with the isopropyl alcohol) then you'd have to make a solution (~ 5% w/v) of baking soda. Isopropyl alcohol (rubbing alcohol) has a very distinctive smell, so it should be immediately obvious which solution is isopropyl. Otherwise, you could measure boiling points of solutions again - isopropyl alcohol has a relatively low BP (it's very volatile that's why you smell it at room temperature). The only solution left, of course, would be water.

I've provided a good start for you - i think you can figure out the rest.

Answer 2

Dip a finger in each one at the same time.
Gently blow on them. The one that feels coolest will be the Alcohol, due to its more rapid evaporation removing the most heat.
Smell the other 3 fingers. Vinegar contains acetic acid...you should recognise the vinegar smell.
For the other two, place about 10 mL of one of them on a saucer and place in the oven until it dries. If it is the salt water, a deposit of salt crystals will be in the saucer. If not, the other is the salt water.

Answer 3

First, I would get some chamber that could maintain a temperature around -1 deg C. Place samples of each liquid in the chamber. If the liquid freezes, it is water.

Second, get some closed container that can be heated and the temperature monitored. Heat a sample of each liquid. If the liquid boils at the boiling point of iso-propyl alcohol, it is iso-propyl alcohol.

Thirdly, get some sodium carbonate. Add it to samples of the two left over liquids and stir. If the liquid "fizzes", it is vinegar.

If the liquid passes all these tests, it is salt water. Dip a hard boiled egg in it and enjoy.

Answer 4

You do need help... you won't get too much detail from me (being a chem teacher) but here are a couple of hints...

Vinegar will bubble when you add baking soda (the others wont).
Salt will precipitate out when water evaporates.
Alcohol evaporates faster than water and it will ignite near a flame.