CHEM TEST - Titration, making salts, extracting metals, Ions + neutralisation, Electrolysis, Titrations, Reactivity Series

W/ practical

What Group is Chlorine in?

Group 7

What is Electrolysis?

Using electricity to split a compound

Why won’t some displacement reactions occur?

Because some of the elemnts have a higher reactivity than the other elements that’s trying to displace them

What is the proper name for a positive electrode?

Anode

What is the name of the thing that attracts to the anode

The anion

What is the proper name for a negative electrode?

Cathode

What is the name of the thing that attracts to the cathode?

The cation

What does pH stand for?

Power of Hydrogen

The pH of an acid or alkali is a measure of the concentration of…………ions

Hydrogen

A pH change from 4 to 2 increases H+ concentration by a factor of…..

100

The pH of a strong acid is……….. than the pH of a weaker acid if they have the same……….

Less, Concentration

What ions do acids produce in aqueous solutions?

H+

What ions do alkali produce in aqueos solutions?

OH-

Why is aliminuim oxide mixed with cryolite?

To lower its melting point

Why can aliminuim not be extracted by carbon?

Carbon is less reactive than aliminium

Strong acids are (completely/partially) ionised in an aqueous solution - Pick the right one

Completely ionised

A weak acid is (completely/partially) ionised in an aqueous solution - Pick the right one

Partially

In sodium chloride solution, hydrogen forms at the cathode and chlorine forms at the anode. Why does Hydrogen form at the cathode and not Sodium?

Because sodium is more reactive than hydrogen

In sodium chloride solution, hydrogen forms at the cathode and chlorine forms at the anode. Why does chlorine form at the anode?

Because Chlorine is in Group 7

What are the tests for chlorine?

Litmus paper. And it turns from blue to white

What are the tests for hydrogen?

The squeakpy pop test.

The concentartion of an acid is…

a measure of the number of hydrogen ions in a solution

Describe how aliminuim is extracted by electrolysis:

Electrolysis splits these compunds. The oxygen goes through the process of oxidation (losing electrons) and attracts to the anode as it becomes a negative ion. Aliminium attracts to the cathode and goes through the process of reduction (gaining electrons)

What does OILRIG stand for?

Oxidation is Losing electrons, Reduction Is Gaining electrons

What is Titration

A way to measure the amount of a substance by reacting it with a known amount of another substance.

First step of titration practical:

1) Use pipette to transfer 25cm³ of sodium hydroxide solution and it will pour into the conical flask

What does the conical flatk do?

Reduces risk of splashing

Second step of titration practical:

2) Add 5 drops of indicator which will be to the alkali in the conical flask

Third step of titration practical:

3) Place conical flask on a white tile so seeing the colour change will be more visible

Fourth step of titration practical:

4) Fill burette w/ sulfuric acid

Fifth step of titration practical:

5) Add acid to the alkali until the solution is nuetral. Adjust just enough acid carefully for this to happen. Once slight colour change is seen, you now add acid drop by drop until solution is neutral.

What is it important to do with the conical flask?

We should swirl the solution to make sure the acid and alkali mix.

When neutralisation is showcased in the conical flask what colour will it turn into??

From a clear colour to pink

Sixth step of titration practical:

6) Read volume of acid added from the burrette that made the solution neutral. Take multiple measurements than find the mean for a total volume.

What do you do first before the actual/proper titration practical?

Do rough titration first.

Which one is more reactive, Sodium or Iron?

Sodium

List the reactivity series of elements

Potassium, sodium, calcium, magnesium, aluminium, zinc, iron, lead, copper , silver, gold

Metals can be arranged in a reactvitiy series based on their reactions w/ water and dilute……………. What one word completes the sentence?

Acids

What is the name of the main compound found in an iron ore?

Iron oxide or haemtite

Look at this list of metals: copper, sodium, iron, zinc, calcium. Which is the third most reactive?

Zinc

Which element is sused to reduce metal oxides and make pure metals?

Carbon

If copper is placed in a solution of zinc sulfate, will the zinc be displaced?

No

Explain why copper doesn’t displace zinc

Copper is less reactive than zinc. A metal that has a lower reactivity than another metal will never displace the original solution.

Will sodium displace iron from iron oxide?

Yes

Why would sodium displace iron from iron oxide

Because sodium is more reactive than an iron . So the sodium will replace iron in the compound.

Which of the following metals would react most vigorously with dilute hydrochloric acid? Copper, Calcium or Zinc

Calcium

Explain why calcium reacts moire vigorously with dilute hydrochloride acid than Copper and Zinc

Because calcium is more reactive than zinc and copper