Introduction To Organic Chemistry

Question 0

3.00g of ethane contains 2.40g of carbon, Ar=12.0, and 0.600g of hydrogen, Ar=1.0. What is the empirical formula?

Answer 0

Number of moles of carbon= 2.40/12.0 =0.200mol
Number of moles of hydrogen=0.600/1=0.600mol
Dividing through by the smallest number gives…
C:H as 1:3
So CH3

Question 1

Define the empirical formula

Answer 1

The simplest whole number ratio in which the atoms in a compound combine together.

Question 2

Define the molecular formula

Answer 2

A formula that tells us the numbers of atoms of each different element that make up a molecule of its compound.

Question 3

What formula shows every atom and every bond in the molecule?

Answer 3

Display formula

Question 4

What is this an example of?

CH3CH2CH2OH

Answer 4

Structural formula

Question 5

Define structural formula

Answer 5

A way of writing the formula of an organic compound in which bonds are not shown but each carbon atom is written separately with the atoms or groups of atoms attached to it.

Question 6

A compound compromising only carbon and hydrogen, in which 4.8g of carbon combine with 1.0g of hydrogen, has a relative molecular mass of 58.
How many moles of carbon are there in 4.8g?
How many moles of hydrogen are there in 1.0g?

Answer 6

0. 4 mol

1. 0 mol

Question 7

How many carbons and hydrogens on the side chain propyl?

Answer 7

C3H7

Question 8

What’s the suffix of ketones?

Answer 8

-one

Question 9

What’s the suffix of haloalkanes?

Answer 9

None

Question 10

What’s Suffix of aldehydes?

Answer 10

-al

Question 11

Which is the correct way of writing the name?

2-methylpentane
Or
2,methylpentane

Answer 11

2-methylpentane

Question 12

What is a locant?

Answer 12

The number used to tell us the position of any branching in a chain and the position of any functional group.

Question 13

In 2-bromo-1-iodopropane

Why is the broom written before the iodo?

Answer 13

Groups are written in alphabetical order.

Question 14

What does di-,tri- and tetra mean?

Answer 14

2,3 or 4 of the same substituting group.

Question 15

Define homologous series?

Answer 15

A set of organic compounds with the same functional group. The compounds differ in the length of their hydrocarbon chains.

Question 16

What’s the general formula for Alkanes?

Answer 16

CnH2n+2

Question 17

What’s the general formula for alkenes?

Answer 17

CnH2n

Question 18

Why do melting and boiling points change as yo increase the number of carbons?

Answer 18

Intermolecular forces increase.

Question 19

Chain branching generally reduces melting points because the molecules pack together less well.

True or false?

Answer 19

True.

Question 20

What’s the names of…?

CH3CH2CH=CHCH3

Answer 20

Pent-2-ene

Question 21

What’s the name of…?

CH3CH2CH2CH(CH3)CH3

Answer 21

2-methylpentane

Question 22

Define structural isomerism

Answer 22

As having the same molecular formula but different structural formulae.

Question 23

Describe positional isomerism

Answer 23

The functional group is attached to the main chain at different points.

Question 24

Functional group isomerism is when there are different number of functional groups.

True or false

Answer 24

False-

is when there are different functional groups

Question 25

Chain isomerism, is when the hydrocarbon chain is arranged differently.

True or false

Answer 25

True