Solutions

A solution is when a substance is dissolved in another substance. A successful solution has the solute mixing freely in the solvent.

Preliminary action,

make tea in a beaker or in small petri dishes observe a small number of coffee granules diffuse.

Some water was placed in a beaker, and its mass was measured using a balance.The mass of water was 200 g. Then 11 g of sugar was weighed out. The sugar was added to the water, and sank to the bottom. 10 minutes later the sugar could not be seen.

Carry out this claim and see if it is true

Calculate the density of this mix

What is happening when sugar or salt get dissovled in water.

http://www.chemit.co.uk/default.aspx?sitemapID=57

OC14 use cobalt chloride paper or

anhydrous copper sulfate to test for water

Cobalt(II) chloride refers most commonly to the inorganic compound with the formula CoCl₂·6H₂O, which when hydrated is deep rose. Because of this dramatic color change and the ease of the hydration/dehydration reaction, "cobalt chloride" is used as an indicator for water in desiccants. The rose hexahydrate is one of the most common cobalt compounds in the laboratory.

http://en.wikipedia.org/wiki/Cobalt(II)_chloride

Add up the total masses

Conclusion

the solubility of substance is ___ grams per 100 ml of pure water

solubilities

NaCl 359g / l

CuSO4 361 g/l

OC16 examine the difference between a dilute, concentrated and saturated solution

OC17 grow crystals using alum or copper sulfate

try it out from here ??

http://www.practicalchemistry.org/experiments/making-a-crystal-garden,193,EX.html

Method

1. Dissolve some crystal making substance in some water.

2. Mix so the substance is completely dissolved

3. Pour a little of the solution into evaporating dishes

4. Heat the Evaporation dishes with the solution (what will happen??)

5. Stop heating when very little liquid is left.

6. Observe.

Results

Draw a diagram of the Crystals

Conclusions

Copper Sulphate forms crystals when the excess water is removed, and goes white if the crystals are heated to much.

What dissolves ? (might be good after ionic bonds)

http://www.sciencebyjones.com/solubility_rules.htm

D5: Blue Glow

A colourless liquid and a blue liquid when mixed together emit a blue

chemiluminescent glow. Light sticks are devices that produce a 'coolight' by means

of a similar chemical reaction.

l Preparation time 30 minutes

l Demonstration time less than five minutes

Requirements

4 g sodium carbonate (anhydrous), Na₂CO₃

3 litres of distilled water

0.2 g luminol (3-aminophtalhydrazide), C₈H₇O₂N₃

24 g sodium hydrogencarbonate NaHCO₃

0.5 g ammonium carbonate monohydrate, (NH₄)₂CO₃.H₂O

0.4 g copper(II) sulphate pentahydrate, CuSO₄.5H₂O (harmful)

50 cm3 10 vol. hydrogen peroxide, H₂O₂

2 x 1 litre flasks

3 litre conical flasks or round bottomed flask with rubber stoppers

glass funnel (15-20 cm in diameter)

ring stand and glass spiral or transparent tubing (see diagram)

Method

Solution A

Dissolve 4.0 g of sodium carbonate in 500 cm3 of distilled water.

Add 0.2 g of luminol and stir to dissolve. Add 24 g of sodium hydrogencarbonate,

0.5 g of ammonium carbonate and 0.4 g of copper sulphate. Stir until all the solid dissolves.

Dilute to a final volume of 1 litre with distilled water. The pH of this

solution will be around 9.

Note: this solution must not be made more than 10 minutes in advance of the demonstration.

Solution B

Dilute 50 cm3 of 10 vol. hydrogen peroxide to 1 litre with distilled water.

Set up a funnel and spiral apparatus either using a glass spiral or transparent tubing

coiled around a set of clamps. See diagram on page 92.

Demonstration

1 Dim the lights but allow sufficient light to see what you are doing! Slowly pour

solution A and B simultaneously into the funnel. A strong blue glow will be

observed.

2 Continue pouring until both flasks are empty. The glowing liquid runs through the

spiral and collects in the 3 litre conical flask. The solution will continue to glow

for approximately 2 minutes after it first exits the spiral.

3 Flush out the coil with water as soon as possible, before disconnecting the

apparatus.

Take a clean beaker, keeping it dry fill the beaker as high as will not spill.

Place the beaker on some paper tissue

A beaker is filled to the brim with water,

slowly sprinkle 20 grams of salt into the beaker

what do you think will happen ?

What happened?

Solutions are different chemicals mixed,

these substances must be miscible to make a solution

Measure out 50 cm² of Water

Measure out 50 cm² of Alcohol.

What will happen when you pour one measure on the other ?

place in beaker shake and settle.

What do you notice?

Why does this happen?

Is it the same for the water and alcohol

Why does this happen? .... molecules

Some materials do not dissolve in water they are said to be immiscible.

Immiscible liquids i.e. liquids that do not mix, liquids that will remain separated e.g. water, oil and mercury

How much co2 is in a fizzy drink?

Find mass of bottle of pop

Find mass of beaker

open bottle

Find mass of bottle of pop

gentaly pour drink into beaker,

find mass of beaker and pop

find mass of empty bottle

add in 2g additions salt.

This could be expanded by testing the same on sugar,

How could you find the amount of sugar in a bottle of fizzy drink??

O2 and CO2 concentrations in water

Gas collecting apparatus, Test tubes, Lime water, Splint, Hot plate

Boil the water

Collect and test for both gases

Record results.

Solubility of O2 in water at different temperatures.

Water sample. Hot plate. Gas collecting apparatus. Graduated test tubes.

Choose three different temps.

Replace graduated test tube for each increase in temp.

Test for O2.

Interesting and educational

http://www.practicalchemistry.org/experiments/introductory/mixtures-and-separations/chemicals-from-seawater,195,EX.html