Solvents

Question 1

strength of london dispersion forces

Answer 1

weak intermolecular force

Question 2

strength of dipole-dipole forces

Answer 2

intermediate strength

Question 3

strength of hydrogen bonding

Answer 3

strong interaction

Question 4

solute

Answer 4

This is the substance that gets
dissolved. It can be a solid, liquid, or even a gas. Think of it as the “guest” in the mixture.

A substance dissolved in a solvent to form a solution

Question 5

solvent

Answer 5

This is the substance that does the
dissolving. It’s usually present in a larger amount compared to the solute and acts as the “host” in the mixture, providing the medium for dissolving
the solute.

The dissolving medium of a solution

Question 6

polarity of hydrocarbons

Answer 6

In general hydrocarbons are non polar

Question 7

Aprotic solvent definition

Answer 7

incapable of donating a proton

Answer 8

In general compounds containing ketones (C=O) and ethers
(C-O-C) are polar ———- Dipole-Dipole interactions

Organic Compounds
Containing-Ketones,
Aldehydes and Ethers

From the electronegativity table C-O bond is polar covalent bond

Answer 9

Polar protic solvents tend to have high dielectric constants and high dipole moments.

Furthermore, since they possess O-H or N-H bonds, they can also participate in hydrogen bonding.

Answer 10

Polar compounds dissolve in Polar compounds and

Non-Polar compounds dissolve in Non-polar compounds

Answer 11

1. Solute molecules are separated from each other.

Solute–Solute attractions resist this.

2. Solvent molecules are separated from each other.

Solvent–Solvent attractions resist this.

3. Solute and solvent molecules mix with each other.

Solute–Solvent attractions assist this.

Answer 12

Each one of these has a particular energy called (H) in this case it is
Heat energy (called Enthalpy) a change in heat energy is (triangle symbol)H

Question 13

Molecular substances will dissolve in each other if:

Answer 13

1. H initial and H final are of similar energy H
2. Both solute–solute attractions and solvent–solvent attractions are weak so
   that there is little resistance to the tendency to mix
3. The solute–solvent attractions are sufficiently strong to overcome the
   resistance to mixing due to solute–solute and solvent–solvent attractions

Question 14

What other factors are helping in the formation of one substance dissolving
in another?

Answer 14

Energy systems have a tendency to increase their Entropy (S).

Entropy S is a measure of disorder

The universe is moving towards greater disorder or larger Entropy

Applied to our system the solute and solvent has a natural tendency to mix
or move towards greater disorder

Answer 15

The universe is moving towards greater disorder or larger Entropy
Applied to our system the solute and solvent has a natural tendency to mix
or move towards greater disorder

Answer 16

The same reason why N2 and O2 do not move towards more order by separating
out in the room. Probability of disorder or the permutations are larger

Question 17

Miscible

Answer 17

If substances are soluble in one another

Question 18

Are Ethanol and Water miscible?

Answer 18

1. Ethanol and Water are miscible because, They form hydrogen bonds between each other

Question 19

Are Hexane and Octane miscible?

Answer 19

2. Hexane and Octane are miscible because,
   The have form weak London dispersion forces between each other and begin with only
   weak Hexane-Hexane and Octane-Octane dispersion forces

Question 20

3. Hexane and Water are immiscible because:

Answer 20

The hydrogen bonds in water prevent the mixing

The hexane-hexane interaction has only weak London dispersion force and overall the mixed system (if it
existed) would have far greater energy than the combined Hexane-Hexane and Water-Water systems

Answer 21

As the non-polar end of any alcohol is increased so does its chances of being soluble in a nonpolar molecule. And less chance of being soluble in water

Question 22

oxidise reaction

Question 23

acid-base reaction

Question 24

chemical change macrosopic

Answer 24

a change in colour
* a change in temperature
* the evolution of heat
* a change of phase (e.g.
precipitation of a solid out of a
solution)
* the emission of light.

Answer 25

Stoichiometry is concerned with the relative amounts of reactants and
products in a chemical reaction.

Question 26

M = m/n

Answer 26

M = molar mass (in grams/mol)
m = is mass in grams
n = is the number of mols (in mols)

Answer 27

The mole ratio allows us to convert from moles of one substance in a
balanced equation to moles of a second substance in the equation.

Question 28

mole to mass conversion importance

Answer 28

1.Determining Reactant Quantities
2.Predicting Product Yields
3.Quality Control in Manufacturing
4.Environmental Applications

Question 29

Moles From Mass

Answer 29

n = 10.0 g / 18.02 g/mol = 0.555 mol

Question 30

Converting Moles to Mass

Answer 30

m = n x M = 2.5 mol x 32.00 g/mol = 80.0 grams

Question 31

To determine the mass of product that will be produced when you
react 10.0 g of A with 10.0 g of B.

Answer 31

The mole ratio between A, B, and the product they form. In other words, we
need to know the balanced reaction equation.
▪ The molar masses of A, B, and the product they form.

Question 32

reaxction where solid forms

Answer 32

A reaction in which a solid forms is called a precipitation reaction.

Question 33

Predicting precipitates

Answer 33

1. Write the reactants as they actually exist before any reaction occurs.
   Remember that when a salt dissolves, its ions separate.
2. Consider the various solids that could form. To do this, simply
   exchange the anions of the added salts.
3. Use the solubility rules to decide whether a solid forms and, if so, to
   predict the identity of the solid

Question 34

Spectator ions

Answer 34

Spectator ions are aqueous ions that don’t participate in reactions: