Organic Chem Revision

Question 1

What steps are needed to determine the empirical formula given percentages

Answer 1

1. Draw a table with percentages
2. Divide percentages by MM
3. Divide by the smallest number so one of the values is 1
4. Multiply all to get whole numbers if easier

Question 2

What is the difference between saturated and unsaturated compounds?

Answer 2

Saturated compounds have ONE single bond only whereas unsaturated may have double or triple bonds

Question 3

Why are ball and stick models preferref to space-filling models?

Answer 3

The latter does not show the nature of chemical bonding very clearly (think blobs stuck together vs models in class)

Question 4

What is the difference between aromatic and aliphatic hydrocarbons?

Answer 4

Aromatic hydrocarbons contain one or more benzene rings whereas aliphatic compounds do not

Question 5

REMINDER: Can you use a curve in a graph?

Answer 5

Yes.

Question 6

What is another name for the O-H functional group?

Answer 6

hydroxyl group

Question 7

What is another name for the C=O functional group?

Answer 7

carbonyl group

Question 8

How can the strength of a carboxylic acid be increased?

Answer 8

By substituting a highly electronegative atom
such as a halogen onto the hydrocarbon chain. As the number of substituted atoms increases, so does the strength of the acid. This is because the strong electron-attracting power of the substituent weakens the oxygen–hydrogen bond and makes it easier to form H+ ions.

Question 9

Can you extrapolate graphs?

Answer 9

If you do, you must use a dotted line

Question 10

What is required in oxidation?

Answer 10

H+/KMnO4-, HEAT

Question 11

Which reaction requires reflux and is an equilibrium?

Answer 11

Esterification

Question 12

What is the difference between volatile and flashpoint chemicals?

Answer 12

Some liquids are volatile, which means that they readily produce vapor, and they can become a fire hazard. Flash point is the minimum temperature to which a liquid must be heated to produce enough vapor to allow a vapor flash to occur

Question 13

What are the differences between acute and chronic poisoning?

Answer 13

Acute toxicity is generally thought of as a single, short-term exposure where effects appear immediately and are often reversible. Chronic toxicity is generally thought of as frequent exposures where effects may be delayed (even for years) and are generally irreversible. Chronic toxicity can also result in acute exposures, with long term chronic effects.

Question 14

How does reflux work?

Answer 14

Reflux involves heating the chemical reaction for a specific amount of time, while continually cooling the vapour produced back into liquid form, using a condenser. The vapours produced above the reaction continually undergo condensation, returning to the flask as a condensate

Question 15

What are the products of esterification?

Answer 15

An ester and H2O

Question 16

What is the difference between an organic and inorganic acid?

Answer 16

Organic acids contain C atoms and must be weak whereas inorganic carbons can be strong or weak