workbook 4

Question 1

what are the 2 types of bonds

Answer 1

intramolecular and intermolecular

Question 2

intramolecular bonding

Answer 2

inside the molecules and between the atoms

Question 3

which type of bonding is stronger

Answer 3

intramolecular

Question 4

what are the 3 types of intramolecular bonding

Answer 4

metallic (sea of electrons), ionic (electron transfer) and covalent (electron sharing)

Question 5

what is normally the strongest type of chemical bond

Answer 5

metallic

Question 6

intermolecular bonding

Answer 6

bonds between the molecules

Question 7

metallic bonding in terms of solubility

Answer 7

Due to strong electrostatic attraction between metal ions and valance ions, metals are insoluble in water but will dissolve in acids.

Question 8

ionic bonding in terms of solubility

Answer 8

These bonds are too strong to dissolve – in green sheet

Question 9

covalent molecular bonding in terms of solubility

Answer 9

They are basically pushed apart into smaller pieces of the same molecule. Usually if an organic or covalent compound is small it’s more likely to dissolve.

Question 10

solvent

Answer 10

does the dissolving – usually a liquid

Question 11

solute

Answer 11

is dissolved – usually the solid

Question 12

solution

Answer 12

homogeneous mixture – made of the solute and solvent, can be a solid, liquid or gas

Question 13

unsaturated solution

Answer 13

a solution which contains less than the quantity of solute needed to saturate it under existing conditions of temperature and pressure

Question 14

saturated solution

Answer 14

one in which no more solute will dissolve under existing conditions of temperature and pressure

Question 15

supersaturated solution

Answer 15

solution which contains more solute than a saturated solution could normally hold under the existing conditions

Question 16

solubility

Answer 16

tells you how saturated a solution is

Question 17

dilute

Answer 17

contains very little solute in relation to the amount of solvent

Question 18

concentrated

Answer 18

contains very little solution in relation to the amount of solvent

Question 19

concentration

Answer 19

refers to the amount of solute dissolved in a certain amount of solvent

Question 20

saturated vs unsaturated

Answer 20

ratio of g per 100ml

Question 21

what is a factor affecting solubilty

Answer 21

temperature

Question 22

how does increasing temp affect solubility

Answer 22

increases the solubility of solids

decreases the solubility of gases

Question 23

what are aqueous solutions

Answer 23

Aqueous solutions are solutions in which the solvent dissolves in water (aq)

Question 24

what are strong electrolytes

Answer 24

A strong electrolyte occurs any time you have an ion even if there isn’t very many of them

Question 25

eg of strong electrolytes

Answer 25

all ionic substances and strong acids –HCl, HNO3, HSO4

Question 26

what s a strong electrolyte equation and an example

Answer 26

There is a single arrow showing all the solid is dissolved completely Eg equation: NaCl --> Na+ + Cl-

Question 27

what are weak electrolytes

Answer 27

Weak electrolytes only partially ionise as some molecule dissolve to ions and some ions reform to molecules. This is shown using a double arrow.

Question 28

eg of weak electrolytes

Answer 28

all weak acids and bases usually covalent molecular substances

Question 29

what is a weak electrolyte equation and an example

Answer 29

a double arrow. Eg equation: Nitrous acid, HNO2 <---> H+ + NO2-

Question 30

what is a non electrolyte

Answer 30

When solids dissolve and no ions are produced

Question 31

eg of non electrolyte

Answer 31

Usually, covalent molecular substances that aren’t weak acids or bases organic substances: glucose, sucrose

Question 32

what lets substances conduct

Answer 32

ions

Question 33

what is a dissociation reaction

Answer 33

Ionic compounds dissociate into their ions when they dissolve in water The ions that are already present have been separated

Question 34

what is an ionisation reaction

Answer 34

Covalent molecular bonds such as strong acids undergo ionisations reactions when they dissolve in water Ions are created from a molecule HCl (g) ---> H+ + Cl- Weak covalent molecular substances show both ions and molecular substances present in solution HF <----> H+ + F-

Question 35

what is the difference between dissociation and ionisation reactions

Answer 35

Dissociation: ions that are already present in the solid are separated and move into solution Ionisation: covalent molecular substances react to form ions which are separated in solution.

Question 36

what is the unit for gram per litre

Answer 36

g L-1

Question 37

unit for parts per million

Answer 37

ppm

Question 38

unit for percentage composition by mass

Answer 38

%

Question 39

unit for moles per litre

Answer 39

mol L -1

Question 40

dilutions in equations does affect the number of moles in the equation so the formula is

Answer 40

N(X) before dilution = n(X) after dilution

Question 41

writing ionic equations

Answer 41

Do not include water in these equations as the (aq) represents the presence of water. Separate the ions when writing out the equation Cross the unchanged Write out what is left Balance Make sure the charges are balanced

Question 42

what are limiting reagents

Answer 42

In most situations where a chemical reaction is performed one of the 2 reagents will be present in excess i.e. some of it remains when the reaction is finished. The reagent that is fully consumed is known as the limiting reagent.