Just General Stuff Really (mostly N5 Knowlege)

Question 1

Do saturated compounds have a higher or lower melting point than unsaturated compounds?

Answer 1

As saturated fatty acids are packed together more tightly than unsaturated fatty acids, saturated fatty acids have higher melting points

Question 2

Compounds containing only single carbon to carbon bonds, like the alkanes and cycloalkanes, are described as…

Answer 2

saturated

Question 3

What is a saturated compound?

Answer 3

A compound in which all carbon to carbon covalent bonds are single bonds.

Question 4

Compounds containing at least one carbon to carbon double bond, like the Alkenes are described as …

Answer 4

Unsaturated

Question 5

What is an unsaturated compound?

Answer 5

A compound in which there are carbon to carbon double or triple bonds, such as alkenes, alyknes and vegetable oils

Question 6

Fats are formed from _______ fatty acids

Answer 6

Saturated

Question 7

Oils are formed from _________ fatty acids

Answer 7

Unsaturated

Question 8

What is a ketone

Answer 8

Carbon compounds which contain the carbonyl group (C=O). They are formed from the oxidation of secondary alcohols. Unlike aldehydes, ketones cannot be oxidized using mild oxidizing agents

Question 9

What colour is bromine solution in a saturated compound?

Answer 9

Brown/ orange
Unsaturated compounds will decolourise bromine solution quickly, whereas it will remain a brown colour with saturated compounds.

Question 10

What colour is bromine in an unsaturated compound?

Answer 10

Colour less.
Unsaturated compounds will decolourise bromine solution quickly, whereas it will remain a brown colour with saturated compounds.

Question 11

What does acidified potassium dichromate solution test?

Answer 11

Acidified potassium dichromate solution is an orange solution which changes to green when the alcohol is oxidised.

Question 12

What is produced when primary alcohols are oxidized?

Answer 12

Aldehydes

Question 13

What is produced when secondary alcohols are oxidized?

Answer 13

Ketones

Question 14

What is produced when tertiary alcohols are oxidized?

Answer 14

Tertiary alcohols do not undergo oxidation readily.

Question 15

Hess’s Law

Answer 15

Formula:

Question 16

A reaction is at equilibrium when…

Answer 16

The rate of the forward reaction is equal to the rate of the reverse reaction

Question 17

Chemical formula of Sulfur

Answer 17

S8

Question 18

Chemical formula of phosphorus

Answer 18

P4

Question 19

What is a limiting reactant?

Answer 19

the reactant that is all used up is called the limiting reactant. - it sets a limit on how much product. can form. the reactant that is left over is described as being in excess.

Question 20

The boiling point of chlorine is much higher than argon.
Explain fully in terms of structure and the type of van der Waals forces present, why the boiling point of chlorine is higher than that of argon. (3 marks)

Answer 20

(1 mark) The forces between chlorine molecules are stronger than the forces between argon atoms.

(1 mark) Both these elements are held together by London dispersion forces.

(1 mark) However, Chlorine (Cl2) molecules have more electrons than Argon (Ar) atoms.

Cheat code
-identify the forces are stronger in one than the other
- state the forces
-if they are the same forces then state what makes the bonds stronger (eg. more electrons)
If different forces then state which is stronger (eg. hydrogen bonds are stronger that London dispersion forces)

Question 21

What us the definition of the enthalpy of combustion

Answer 21

Energy released when one mole of substance is burned completely in oxygen