GROUP SKUX: Repost of the indicator experiment

Sorry, the one that i uploaded was their fail one. This is the proper one.

Credit: Liam C-Grove, Ray MC

Acids & Carbonates

Acids and carbonates when they are mixed release carbon dioxide, water and salt.

Acid + Carbonate à Salt + Carbon Dioxide + Water 

Mixtures	Equations	Observations
Hydrochloric Acid + Copper Carbonate	2HCl + CuCO3 ---> CO2 + H2O + CuCl2	When the acid and carbonate mix together there is an immediate reaction as the mixture fizzes up it rises right to the top of the test tube and then suddenly starts to drop back down and goes back to a liquid, then about 20 seconds later it has started to change from an originally green cloudy colour to a clear light blue
Hydrochloric Acid + Magnesium Carbonate	2HCl + MgCO3 ---> CO2 + H2O + MgCl2	When the acid and carbonate mix together there is an immediate reaction as the mixture fizzes up it rises to about half way up the test tube and then suddenly starts to drop back down and goes back to a cloudy milky coloured liquid, unlike the copper carbonate solution this mixture doesn’t go back to a see-through clear liquid it remains cloudy with the milky colour.

Metal carbonates normally react with acid to form different types of salts, carbon dioxide and water. A metal carbonate is a type of metal that is made as a result of a mixture between carbon and oxygen. Hence the equation.

Acid + Carbonate ----> Salt + Water + Carbon Dioxide

GROUP SKUX (Ray MC, Liam C-Grove, Mady, J-Chan, T-Roar)

pH Scale & Indicators

pH Scale:

The pH scale is used to determine whether a substance is either acidic or basic. We want to find this information because it is important in determining if the substance can be applied to something. To find this out, you must add drops of Universal Indicator to the substance.
The pH scale has different colours and numbers to indicate this; the scale runs from 1 - 14.
However, the acids are from 1.0 - 6.9 (Pink - Yellow).


Litmus paper also helps to indicate acids and bases. The special paper turns either blue or red depending if it is an acid or a base. Blue for a base, red for an acid.

Credit: J-Chan

The reaction between acids and metals

when metals reacts with an acid they produce hydrogen and a salt e.g. sulfate, nitrate, chloride and ethanoate. in our experiments we used the same metal (magnesium) and reacted it with four different acids.
Facts:

• ·        Metal + acid = salt + hydrogen
• ·        Metals like copper and salt do not react with dilute acids
• ·        Reactive metals like lithium, sodium, potassium and calcium react violently with dilute acids
• ·        (H2) hydrogen is colourless and odourless. You may be able to hear a squeaky pop sound when a burning splint is held over a test tube which has hydrogen gas present.
• ·        Nitrate, chloride, ethanoate and sulfate are all types of salts

Reactions:

• ·        Ethanoic acid + magnesium strip = magnesium ethanoate + hydrogen

You know that a reaction has occurred due to violent fizzing, a release of heat, the substance becomes cloudy, the magnesium strip begins to corrode before disappearing, changes to an orange colour.

• ·        Sulphuric acid + magnesium strip = magnesium sulphate + hydrogen  

Reaction has occurred when magnesium is floating at the top of the substance, it begins to bubble and become cloudy, changes colour to a pink rather than red, magnesium strip may disappear

• ·        Hydrochloric acid + magnesium strip = magnesium chloride + hydrogen

Reaction has occurred when the substance begins to bubble and turn cloudy, magnesium floats to the surface before gradually disappearing, less violent than ethanoic reaction, the substance heats up as the hydrogen gas levels increase, changes colour to red

• ·        Nitric acid + magnesium strip = magnesium nitrate + hydrogen

Reaction has occurred when the substance begins to fizz and bubble, turns a red colour before going yellow, goes cloudy, mixture begins to warm, magnesium sinks to the bottom before disappearing

  Equations:

Mg_(s) + 2CH₃COOH_(aq) --> Mg(CH₃COO)_2(aq) + H_{2 (g)}
H2SO4 + Mg = MgSO4 + H2

2HCl + Mg = MgCl2 + H2

2HNO3 + Mg = Mg(NO3)2  + H2

       

Magnesium fizzing in hydrochloric acid

The final results of the reactions listed above

   

Acids used in the experiments above

Isotopes

Some elements have isotopes - atoms with different mass numbers, so different numbers of neutrons. For example, chlorine has a relative atomic mass of 35.45. This means that the average mass of all chlorine atoms is 35.45. From this we can infer that the most common isotope of chlorine has a mass of 35, but there must also be isotopes with a higher mass, such as 36 or 37.

Sodium Reaction Wed 3/6

If this doesn't work try the link here

http://www.youtube.com/watch?v=2T3Ll__C09w