Organic chemistry

What carbon compounds are not part of organic chemistry?

CO, CO2, H2CO3, carbonates (CO3 2-) and hydrogencarbonates (HCO3-)

Do compounds in a homologous series show similar chemical properties?

Yes

Do compounds in a homologous series have the same functional group?

Yes

Do compounds in a homologous series have the same general formula?

Yes

Do compounds in a homologous series show gradation in phyisical properties?

Yes

Are compounds in a homologous series differenciated by a CH2 group

Yes

What is the role of the functional group?

They determine the chemical properties of the compound

What is a general formula ?

The formula that describes all members of a homologous group (alkanes: CnH2n+2)

What are structural isomers

compounds with the same molecular formula but different arrangement of atoms.

What are the names for 1,2 and 3 numbers of atoms? (Respectively)

Meth, Eth, Prop

What are the names for 4,5 and 6 numbers of atoms? (Respectively)

But, Pent, Hex

What are the names for 7,8 and 9 numbers of atoms? (Respectively)

Hept, Oct, Non

How are alkanes named?

Preffix (number of atoms) + Suffix (ane)

What intermolecular forces do alkanes have?

Only london dispersion forces (they are nonpolar)

Why do longer alkanes have more intermolecular forces?

More carbon atoms means more surface area and thus reaction.

Why is it harder to break longer chain alkanes?

The bigger the molecules, the more electrons and the greater distortion of the electron cloud, thus making london dispersion forces harder to break

Why do alkanes show gradation in phyisical properties?

More carbon atoms means more intermolecular forces and thus more boiling point

What is the effect of increased london dispersion forces on alkanes?

More london dispersion forces eventually turn alkanes into liquids and then into solids.

Do alkanes occur naturally?

yes, they can be found on crude oil.

When naming alkanes, which is the parent chain?

The longest continuous chain (including turns)

Should side chains be named alphabetically?

Yes. Ethyl before Methyl. Not in order of number of atoms.

When naming alkanes, from which side should you start?

The end that gives the smaller number or and is closer to a side branch.

What are IUPAC rules to name alkanes?

Indicate the position of the side chains by numbering carbon atoms in the main chain. From end to branch.

Do unbranched compounds have a higher boiling point and more intermolecular forces?

Yes. Because there are no gaps, more london dispersion forces can act. More surface area equals more reaction

Are alkanes soluble?

They are not soluble in water (polar) but they are soluble in nonpolar compounds. Alkane dissolution in water is not energetically favoured because hydrogen bonds are hard to break

What is cracking?

When crude oil is separated by fractional distillation and longer chain alkanes are broken into smaller ones through high temperature, absence of air, and a catalyst.

Why is termal cracking not popular?

It utilises high temperature and pressure, which can be costly and dangerous.

Why is catalytic cracking more common?

It uses low temperature, low presusre, and a zeolite catalyst. Not as dangerous or costly.

What is incomplete combustion?

When there is no sufficient oxygen, it creates byproducts of CO and water or soot and water. Both CO and soot are toxic and can lead to death.

Does halogenation occur in the dark?

No, in the dark, only fluorine will react with alkanes.

What is a free radical?

atom that possesses at least one unpaired electron in the outer shell. They are very reactive.

What is halogenation?

It is a free radical substitution mechanism which occurs in three steps: Initiation, propagation, and termination.

how is free radical substitution initiated?

When UV radiation breaks the halogen into free radicals

What happens in the propagation phase of free radical substituion?

Free radicals collide with molecules, forming new products. One of these products is another radical, which reacts again in a chain reaction. there is homolytic bond fission (molecules broken equally)

What happens in the termination phase of free radical substitution?

Radicals combine to form stable molecules and reaction stops.

What is the general formula of alkenes?

CnH2n

What characterises alkenes?

They are unsaturated and have a C=C functional group

are alkenes naturally occuring?

no, they are acquired from fractional distillation and breaking of larger alkanes