Nat 5 Chemistry Part 2

Question 1

What is the general equation when an acid is neutralised by a metal carbonate?

Answer 1

Acid + Metal Carbonate → Metal Salt + Water + Carbon Dioxide

Question 2

What word is used to describe ions that are present during the reaction but are unchanged by the reaction, and so are present in the same state on both sides of the equation?

Answer 2

Spectator ions

Question 3

How would the following ionic equation be rewritten omitting the spectator ions?
H+(aq) + Cl-(aq) + Na+(aq) + OH-(aq) → Na+(aq) + Cl-(aq) + H2O(l)

Answer 3

H+(aq) + OH-(aq) → H2O(l)

Question 4

How would the following ionic equation be rewritten omitting the spectator ions?
2H+(aq) + 2NO3-(aq) + Ca2+(aq) + CO32-(aq) → Ca2+(aq) + 2NO3-(aq) + H2O(l) + CO2(g)

Answer 4

2H+(aq) + CO32-(aq) → H2O(l) + CO2(g)

Question 5

Reactions can be represented using ionic equations.
A: H+(aq) + OH-(aq) → H2O(l)
B: 2H2O(l) + O2(g) + 4e<span>-</span> → 4OH-(aq)
C: 2H+(aq) + CO32-(aq) → H2O(l) + CO2(g)
D: SO2(g) + H2O(l) → 2H+(aq) + SO32-(aq)
E: NH4+(aq) + OH-(aq) → NH3(g) + H2O(l)
Identify the two ionic equations that show the neutralisation of an acid.

Answer 5

A: H+(aq) + OH-(aq) → H2O(l)
C: 2H+(aq) + CO32-(aq) → H2O(l) + CO2(g)

Question 6

What is the purpose of a titration reaction?

Answer 6

This technique is commonly used in neutralisation reactions and to calculate an unknown concentration (of either the acid or alkali).

Question 7

Which titration results should be used to calculate an average volume used?

Answer 7

Concordant results (within 0.2).

Question 8

electrolysis

Answer 8

The process of breaking down of an ionic compound into its elements by the use of an electric current.

Question 9

base

Answer 9

A compound which neutralises an acid to form a salt and water. Bases can be soluble or insoluble. Metal oxides and metal hydroxides are bases. Soluble bases form alkaline solutions

Question 10

lattice

Answer 10

A lattice is a regular grid-like arrangement of ions in a solid ionic compound.

Question 11

Precipitate

Answer 11

The insoluble solid formed in a solution during a chemical reaction.

Question 12

solute

Answer 12

The material that dissolves in a solvent to form a solution.

Question 13

solvent

Answer 13

The liquid in which the solute dissolves in to form a solution.

Question 14

What do ions do in neutralisation reactions?

Answer 14

Change charges

Question 15

What is the step by step titration calculation?

Answer 15

Step 1 Work out the moles

Step 2 Ratio

Step 3 Work out concentration

Question 16

What are the 3 fossil fuels?

Answer 16

Gas, Oil, Coal

Question 17

How is coal made?

Answer 17

From the remains of dead plants. The condition needs to be hot and swampy. A fossil is a dead plant or animal preserved in rock. So scientists call these fossil fuels.

Question 18

How is crude oil formed?

Answer 18

When plankton that lived many years ago and sea plants died layers of mud and slit formed on top of them. Pressure and high temperature cause the remains to slowly change (anaerobic change). Oil and gas are obtained.

Question 19

State things about fractional distillation.

Answer 19

• Crude oil is a mixture of different compounds called hydrocarbons
• Crude oil must be separated into different substances before we can use it
• These substances have similar boiling points and are called fractions.

Question 20

What are the steps for crude oil to be slit into fractions?

Answer 20

1. Crude oil is heated and begins to boil
2. Gases rise up the column
3. The column is hot at the bottom and cooler at the top
4. Hydrocarbons condense at different temperatures depending on their boiling points
5. Then tapped off at the different temperature to give fractions

Question 21

What is viscosity mean?

Answer 21

Viscosity is a measure of a fluids resistance to flow. It describes how thick or sticky a liquid is - higher viscosity means the fluid flows more slowly, while lower viscosity means it flows more easily.

Question 22

Why is the cracking process used?

Answer 22

Crude oil tends to have more long chain fractions than are in demand. To convert them into more useful short chain molecules a process called cracking is used.

Question 23

What is an alkane made of hydrocarbons?

Answer 23

Compounds where the atoms are joined by single covalent bonds. Carbon must have 4 bonds. Hydrogen can only have one bond. Structural formula - CnH(2n+2). Contains mainly carbons and hydrogens.

Question 24

The names for the number 1 - 8 in the homologous series and their memorable sentence.

Answer 24

Meth, Eth, Prop, But, Pent, Hex, Hept, Oct

Monkeys eat peanut butter penguins have horrible organs.

Question 25

What is the homologous series?

Answer 25

A family of hydrocarbons with the same general formula and similar chemical properties.

Question 26

What is an alkene made of hydrocarbons?

Answer 26

Contains at least one double bond. Structural formula - CnH2n.

Question 27

What can unsaturated hydrocarbons have their double bonds broken and used to manufacture.

Answer 27

Polymers

Question 28

Whats the difference between saturated and unsaturated hydrocarbons?

Answer 28

Saturated hydrocarbons contain single bonds Unsaturated hydrocarbons contain at least one double or triple bond

Question 29

What are cycloalkanes?

Answer 29

The same number of carbons in a circle. Less hydrogens. Structural formula CnH2n.

Question 30

What is an isomer?

Answer 30

The same number of carbons and hydrogens although a different look and formula.

Question 31

What are the ways to make isomers?

Answer 31

- Instead of all carbons in a row have branches - Alkenes and cycloalkanes of the same number of carbons will be isomers - For alkenes larger than propene moving the carbon to carbon double bond will make isomers - Combination of above

Question 32

What are the rules for naming isomers?

Answer 32

Rule 1: The longest chain of carbons gives the main part of the name. Rule 2: The location of the branch is given by a number from the carbon in the chain. Rule 3: When numbering a chain starts from the end nearest branch. Rule 4: Every branch must be numbered. Separate numbers with commas. Use prefix di, tri, etc when a branch appears more than once. When numbering a molecule with a functional group. The functional group must be given the lowest number.

Question 33

What is it called when all the carbon atoms lie in a straight line in a hydrocarbon.

Answer 33

A straight chain molecule

Question 34

What are the different branch names?

Answer 34

methyl ethyl

Question 35

What separates the numbers from letters in the naming of homologous stuff.

Answer 35

hyphens ---

Question 36

How is the carbon double bond located in the name.

Answer 36

A number is inserted when there are 4 or more carbons. alk -- number -- ene

Question 37

What does the carbon double bond do for the alkene?

Answer 37

It gives it it's chemical properties.

Question 38

If there is one branch on the cycloalkane what happens?

Answer 38

The branch doesn't get a number. The carbon on the branch is not counted when counting the longest carbon chain.

Question 39

When there are more than one alkyl group what happens?

Answer 39

The groups are numbered with the numbers being as small as possible.

Question 40

What are the 3 different types of compound containing carbon?

Answer 40

Alkanes Alkenes Cycloalkanes

Question 41

State a thing about combustion reactions.

Answer 41

Alkane will produce more water than alkene or cycloalkane.

Question 42

State things about testing for unsaturation.

Answer 42

Alkanes and cycloalkanes will not rapidly decolourise from a few drops of bromine water. The alkene will. Using infra - red analysis to identify the c=c.

Question 43

What is a hydrocarbon?

Answer 43

Hydrocarbon is a compound containing hydrogen and carbon only.

Question 44

Alkenes are more reactive than alkanes because they have a carbon to carbon double bond. What type of reaction occurs when reactants such as Hydrogen or Chlorine attacks and breaks the double bond?

Answer 44

Addition reaction.

Question 45

What is formed when an alkene undergoes an addition reaction with hydrogen?

Answer 45

Alkane

Question 46

What is the name of this compound? H H H H H | | | | | H - C - C - C - C - C - H | | | | | H H H H H

Answer 46

Pentane

Question 47

Which of the following could be the molecular formula of a cycloalkane? A C7H10 B C7H12 C C7H14 D C7H16

Answer 47

C. C7H14

Question 48

What is the test for carbon dioxide?

Answer 48

turns limewater