Year 10 Science - Chemical Reactions– Outline



2015 Year 10 Chemical Reactions

Key Concepts


SCIENCE UNDERSTANDING
Different types of chemical reactions are used to produce a range of products and can occur at different rates. (4-6 lessons)
NAME:

Science Quest
TEXTBOOK
SCIENCE Quest PRACTICALS / ACTIVITIES
SCIENCE Quest
HOMEWORK
OTHER ACTIVITIES/RESOURCES
1
5.1 – A Game of Balance – Develop an understanding of the translation of word equations to symbols in the writing of balanced chemical equations.
Activities in the section p.162 – 164)
- Game Rules
- Play the Game.
Checking for Balance interactivity int-0677 ebook
Questions from textbook p. 164 Qn’s – 1 -3
Worksheet 5.1 – Chemical Equations
Worksheet 5.2 – Balancing Chemical Equations
Worksheet 5.3 - A World of Reactions


https://www.educationperfect.com/login/#Task=84248


Go here for a Valency table and a step by step process of how to balance equations. Courtesy of Mr Warden.


Also a good animation and simulation on how balancing really works from Colorado Uni


Activity: Ionic formulas sheet


Words to Learn
- chemical equations
2.
5.2 –Precipitation Reactions – Develop an understanding of equation writing by completing activities related to precipitation reactions
- Utilise solubility table given on p. 165 to develop students’ understanding of soluble/ insoluble compounds formed and the precipitation reactions related to these precipitates.
Suggestions:
Investigation 5.2 – Will it Precipitate p.166 Qn’s 1 - 5
Questions from textbook p. 166 – Qn’s 1 – 6
Worksheet 5.4 Precipitation
Words to Learn
- ionic compounds, precipitate, precipitation reactions
3
5.3 – Chemicals can be a Health Hazard –
Describe the dangers associated with each of the classes and subclasses of substances classified as dangerous goods. Have students have an awareness of more common chemical symbols encountered.
Read and complete section and p.169 Qn’s 1-6

Words to Learn
- terms used on dangerous goods symbols
4
5.4 – A World of Reactions – students to have an awareness of combustion reactions
external image placeholder?w=200&h=50 hydrocarbons + oxygen carbon dioxide + water
Take appropriate notes
examples of balanced combustion rxtns

5
5.7 –Rates of Reaction– Describe the role of catalysts in a chemical reaction and investigate the use of naturally occurring catalysts in the human body.
Investigation 5.4 – A Liver Catalyst
Read and complete section and textbook questions p. 184 – Qn’s 1-5
Worksheet 5.4 p. 184 - A Liver Catalyst
Words to Learn
- rate, catalyst, enzyme
6
Assessment – completion of 2 practical reports (as above)
- assessment of concepts from relevant exam questions on the Mid Year Exam




Revision


Online test for valency Access Key is
8C7F remember to type your class in front of your first name




Class notes


Class Notes

The law of conservation of matter (mass)This states that matter can not be created nor destroyed. In chemistry this means that when we observe a reaction the elements present at the start of the reaction will also be present at the end of the reaction. They may have combined differnetly and have formed another compound or they may change state.

In an experiment we added calcium carbonate to hydrochloric acid in a closed conical flask while it sat on an electronic balance.
We knew a reaction happened because we saw - bubbles, balloons full of gas and the marble chip (calcium carbonate) got smaller.



The mass at the beginning of the reaction was 205g
The mass after the reaction was _205g__(some student's did not get teh same mass eg 1 group got 204.6g


Why were their masses different? They should not be different. It was expected to be the same.

Any difference may be due to the electronic balance being left on for a long period of time and losing accuracy.

How does this relates to equations of reactions?
The elements in the reactants should be in the same quantity in the product.


This means if our equation shows 1 calcium atom on the reactant side it should have one calcium on the product side. If it does not we have to go through a process called balancing the equations.

The reaction for this experiment is
CaCO3 + 2 HCl ----> CaCl2 + H2O + CO2
This is an example of a carbonate plus an acid reactionBig number at the front of a element or compound means to multiply all the elements in the compound by that number.


A little number behind a letter means you multiply that letter (element) by that number to work out how many atoms of that element are in the reaction.
For more information on how to balance equations go here AND GO HERE FOR AN ANIMATION


Types of reactions
neutralisation reactions
This is when an acid is added to a base. These two compounds neutralise each other and form a salt and water
General form: Acid + Base -----> Salt + Water
Example; Hydrochloric acid + sodium hydroxide -------> sodium chloride + water
HCl + NaOH -------> NaCl + H2O


Examples of acids:hydrochloric acid HCl
Sulfuric acid H2SO4
Nitric acid HNO3
Vinegar or Citric acid CH3COOH


Examples of basesSodium Hydroxide NaOH
Calcium Hydroxide Ca(OH)2
Magnesium Hydroxide Mg(OH)2
metal hydroxide


Practice
Write a balanced equation for sodium hydroxide + Nitric Acid [Hint write the word equation first]
,Write equations for

  1. Mg(OH)2 +H2SO4
  2. Mg(OH)2 +HNO3
  3. NaOH + H2SO4

Combustion Reactions
Combustion reactions is when oxygen is combined with another compound or element. We call this combining burning.
Common example is methane + oxygen ------> Carbon dioxide + water
CH 4 + O2 ----> CO2 + H2O


Precipitationsolution + solution ----> solid + solution Its important to realise that the product of a precipitation reaction is a coloured solid that makes the solution change from a see through solution to an opaque solution. The subscripts s aq l and g are requiredegPb(NO3)2(aq) + KI(aq) --------->PbI2 (s) +2KNO3(aq)

Rates of Reaction
We know a reaction has occured if bubbles of gas are produced, a colour change happens or a temperature change occurs.How fast this happens is called the rate of a reaction. Eg rusting is a very slow combustion reaction. Propane gas burning to heat the BBQ is a very fast reaction.Rate refers to how fast the reaction reaches completion. The expt with liver and peroxide showed that
  • peroxide by itself gave off very few bubbles
  • peroxide with a lump of liver gave off quite a few bubbles
  • peroxide and finely chopped liver gave off lots of bubbles.

In this expt the liver was the catalyst. we increased the rate of the reaction by adding the catalyst. The definition of a catalyst is " a chemical that speeds up a reaction but does not become part of the products in the reactions.We increase the effectiveness of the catalyst by chopping it up - this increased the surface area on which the reaction can take place.

This expt increases the rate by increasing the concentration and the temperature of the reactants.The expt with the sodium thiosulphate and hydrochloric acid reached completion when all the liquid turned a milky yellow.
Size of the particles in a reaction affects the surface area that is exposed to react. For example 10g of calcium carbonate crushed as powder will result in very small particles. These will have a larger surface area when compared to a 10g stone of calcium carbonate (marble)


How would we test this?To ensure it was a fair test we USed same amount of acid and the same mass of calcium carbonate.
The powder was faster because - it has the largest surface area - it would spread out over the desk the furthest. The rock would not spread out.


How Does Temperature affect the reaction rateIncrease in temp leads to increase in reaction rate.
This is because an increase in temperature will increase the kinetic energy of the particles in the reaction making them move faster and bump into more particle sand so more chances of reacting hence the reaction rate is faster.
Biological catalysts
Enzymes are biological catalysts. They speed up rxtns .
Eg digestion of starch involves amylase. Amylase is the enzyme. It speeds up the reactns to break down starch into simple sugars.

Summaryreaction rate is increased if
  1. temperature is increase
  2. concentration of reactants is increase

  3. surface area is increase
  4. use of a catalyst







Carbon ChemistryCarbon chemistry's other name is organic chemistry. It is chemistry of living things and as such it usually only involves the elements - Carbon, Hydrogen and Oxygen ( Nitrogen too in some cases). This means water is an organic compound as is Natural gas - Methane.

The simplest organic chemicals are the hydrocarbons.
Hydrocarbons with single bonds between the Carbons are called ALKANES.
Hydrocarbons with a double bond between one of the carbons are called ALKENES
Hydrocarbons with triple bonds between a pair of carbons are called ALKyNES


The rules
Each carbon atom must have 4 bonds. These bonds are shown as straight lines coming off the letter C - this C represents 1 carbon atom.
On the other end of each stick must be a C or a H ( for hydrogen atom)
Each H can only have 1 stick coming off it.


The Code
The prefix of a word indicates the number of carbon attoms.
meth = 1, eth = 2, prop = 3 but = 4, pent = 5, hex = 6, hept = 7, oct = 8, non = 9, dec = 10


eg propane = means 3 carbon atoms joined by a single bond between the carbons
eg heptane = means 7 carbon atoms joined by a single bond between the carbon atoms
eg butene = means 4 carbons one double bond between 2 of the carbons


Alcohols
The alcohols are not hydrocabons as they have oxygen added to them. We say an hydroxy group has been added to the end of a alkane (or other) chain. The hydroxy group is called the functional group and is denoted in the naming convention by the letters "ol"


eg ethanol = this means 2 carbons in the chain joined by single bonds with an OH group on the end.

Ways to make alcohols naturally include fermentation. We do this when we make beer or wine or whiskey.
There are some problems with making your own alcohol they include increasing the number of impurities in the brew that leads to a higher than required alcohol content or alcohols that are very poisonous.
Eg Methanol - very poisonous - sends you blind
Propanol - very poisonous dissolves cells.
Ethanol is the alcohol in drinks.


A note about fermentation
this is an organic reaction
Glucose -----> carbon dioxide + alcohol


This is the old course
Name

Key Concept

Vocabulary
Common Assessment Tasks
  1. Patterns, order and organization
  2. Form and function
  3. Stability and change
  4. Systems

Different types of chemical reactions are used to produce a range of products and can occur at different rates
Synthetic
plastic
polymer
polymerisation
monomer
copolymer
crosslinks
thermosetting polymer thermoplastic polymers
precipitation
aqueous solution
ionic compounds
combustion reactions
hydrocarbons
decomposition reactions
combination reactions
fossil fuels
fractional distillation biofuels
biomass
biogas
ethanol
catalyst


Regular homework tasks – as determined by individual teachers
Suggested Priority and Timeline

Suggested Activities
Extension and Variation
Week 1
5.1 Form and function: Plastic facts p.196
  • Different types of polymers – definition of monomers, polymers, copolymers, thermosetting and thermoplastic polymers
5.2 A Game of Balance p. 199 – balancing Equations
  • Complete a series of questions to cover balancing chemical equations
  • Inquiry Investigation 5.1 – Making Casein Plastic p. 196.
  • Qn’s 1-9 p.198
Do this firsthttps://www.educationperfect.com/login/#Task=84248
__


  • Qn 7 p. 201 Checking for balance interactivity. int-0677

5.1 Chemical equations
5.2 Balancing chemical equations
5.3 A world of reactions
  • Weblink
Use the Balancing equations weblink in the eBookPLUS to learn more about balancing chemical equations
Extension

  • Qn 11 – Imagine – Creative Writing Activity
  • Qn 12 – Investigate – Practical Design Activity
__
Weeks
2-3
Different types of Reactions
5.3 Precipitation Reactions
5.4 A World of Reactions
- Discuss combustion, breaking down and combination reactions
5.5 The Need for Speed
Discuss catalysts

More ground work on balancing equations
a table of valencies
balancing work sheet 1
Activity: Ionic formulas sheet

Homework Book: 2.1 Writing Formulas (p24-25)/2.1 Ionic compounds p16-17 (DIM BK3)

Go here for a Valency table and a step by step process of how to balance equations. Courtesy of Mr Warden.


Also a good animation and simulation on how balancing really works from Colorado Uni
  • Weblink
Use the Introduction to reactions weblink in your eBookPLUS to find out more about precipitation and other reactions.
  • Inquiry Investigation 5.2 - Will it precipitate?
p. 203
external image placeholder?w=200&h=505.4 Precipitation

  • Inquiry Investigation 5.3- Decomposing powder p. 203
  • Inquiry Investigation 5.5- A Liver Catalyst p.220
Answer Questions 1 – 3 p. 220
5.5 Chemicals can be a Health Hazard
Qn’s 1-7
Week 4
5.6 Fuelling our Lifestyle
Science as a human endeavor
- Discuss fuel sources - fossil fuels, fractional distillation, biofuels, biomass, biogas, ethanol
  • Answer Questions 1-10 p. 217
Qn 15 p. 217
Week 5
END OF TOPIC TEST

STUDY FOR SEMESTER TWO EXAMS
















Class Notes

The law of conservation of matter (mass)

This states that matter can not be created nor destroyed. In chemistry this means that when we observe a reaction the elements present at the start of the reaction will also be present at the end of the reaction.

In an experiment we added calcium carbonate to hydrochloric acid in a closed conical flask while it sat on an electronic balance.
We knew a reaction happened because we saw - bubbles, balloons full of gas and the marble chip (calcium carbonate) got smaller.


The mass at the beginning of the reaction was
The mass after the reaction was ___the same


Why were the masses different? They should not be different

It was expected to be the same. Any difference may be due to the electronic balance being left on for a long period of time and losing accuracy.

How this relates to equations of reactions.
The elements in the reactants should be in the same quantity in the product.


This means if our equation shows 1 calcium atom on the reactant side it should have one calcium on the product side. If it does not we have to go through a process called balancing the equations.

The reaction for this experiment is


CaCO3 + 2 HCl ----> CaCl2 + H2O + CO2 This is an example of a carbonate plus an acid reaction

Big number at the front of a element or compound means to multiply all the elements in the compound by that number.

A little number behind a letter means you multiply that letter (element) by that number to work out how many atoms of that element are in the reaction.
For more information on how to balance equations go here AND GO HERE FOR AN ANIMATION


Types of reactions
neutralisation reactions
This is when an acid is added to a base. These two compounds neutralise each other and form a salt and water
General form: Acid + Base -----> Salt + Water
Example; Hydrochloric acid + sodium hydroxide -------> sodium chloride + water
HCl + NaOH -------> NaCl + H2O


Examples of acids:

hydrochloric acid HCl
Sulfuric acid H2SO4
Nitric acid HNO3
Vinegar or Citric acid CH3COOH


Examples of bases

Sodium Hydroxide NaOH
Calcium Hydroxide Ca(OH)2
Magnesium Hydroxide Mg(OH)2
metal hydroxide


Practice
Write a balanced equation for sodium hydroxide + Nitric Acid [Hint write the word equation first]
,Write equations for

  1. Mg(OH)2 +H2SO4
  2. Mg(OH)2 +HNO3
  3. NaOH + H2SO4

Combustion Reactions

Combustion reactions is when oxygen is combined with another compound or element. We call this combining burning.
Common example is methane + oxygen ------> Carbon dioxide + water
CH 4 + O2 ----> CO2 + H2O

Precipitation

solution + solution ----> solid + solution

Rates of Reaction

Rate refers to the how fast the reaction reaches completion. The expt with liver and peroxide showed that

  • peroxide by itself gave off very few bubbles
  • peroxide with a lump of liver gave off quite a few bubbles
  • peroxide and finely chopped liver gave off lots of bubbles.

In this expt the liver was the catalyst. we increased the rate of the reaction by adding the catalyst. The definitioin of a catalyst is " a chemical that speeds up a reaction but does not become part of thte products in the reactions.
We increase the effectiveness of the catalyst by chopping it up - this increased the surface area on which the reaction can take place.

This expt increases the rate by increasing the concentration and the temperature of the reactants.
The expt with the sodium thiosulphate and hydrochloric acid reached completion when all the liquid turned a milky yellow.
Size of the particles in a reaction affects the surface area that is exposed to react. For example 10g of calcium carbonate crushed as powder will result in very small particles. These will have a larger surface area when compared to a 10g stone of calcium carbonate (marble)


How would we test this?To ensure it was a fair test we USed same amount of acid and the same mass of calcium carbonate.
The powder was faster because - it has the largest surface area - it would spread out over the desk the furthest. The rock would not spread out.


How Does Temperature affect the reaction rateIncrease in temp leads to increase in reaction rate.
This is because an increase in temperature will increase the kinetic energy of the particles in the reaction making them move faster and bump into more particle sand so more chances of reacting hence the reaction rate is faster.
Summary
reaction rate is increased if
  1. temperature is increase
  2. concentration of reactants is increase

  3. surface area is increase
  4. use of a catalyst






Carbon Chemistry

Carbon chemistry's other name is organic chemistry. It is chemistry of living things and as such it usually only involves the elements - Carbon, Hydrogen and Oxygen ( Nitrogen too in some cases). This means water is an organic compound as is Natural gas - Methane.

The simplest organic chemicals are the hydrocarbons.
Hydrocarbons with single bonds between the Carbons are called ALKANES.
Hydrocarbons with a double bond between one of the carbons are called ALKENES
Hydrocarbons with triple bonds between a pair of carbons are called ALKyNES


The rules
Each carbon atom must have 4 bonds. These bonds are shown as straight lines coming off the letter C - this C represents 1 carbon atom.
On the other end of each stick must be a C or a H ( for hydrogen atom)
Each H can only have 1 stick coming off it.


The Code
The prefix of a word indicates the number of carbon attoms.
meth = 1, eth = 2, prop = 3 but = 4, pent = 5, hex = 6, hept = 7, oct = 8, non = 9, dec = 10


eg propane = means 3 carbon atoms joined by a single bond between the carbons
eg heptane = means 7 carbon atoms joined by a single bond between the carbon atoms
eg butene = means 4 carbons one double bond between 2 of the carbons


Alcohols
The alcohols are not hydrocabons as they have oxygen added to them. We say an hydroxy group has been added to the end of a alkane (or other) chain. The hydroxy group is called the functional group and is denoted in the naming convention by the letters "ol"


eg ethanol = this means 2 carbons in the chain joined by single bonds with an OH group on the end.

Ways to make alcohols naturally include fermentation. We do this when we make beer or wine or whiskey.
There are some problems with making your own alcohol they include increasing the number of impurities in the brew that leads to a higher than required alcohol content or alcohols that are very poisonous.
Eg Methanol - very poisonous - sends you blind
Propanol - very poisonous dissolves cells.
Ethanol is the alcohol in drinks.


A note about fermentation
this is an organic reaction
Glucose -----> carbon dioxide + alcohol










-------------------------------------------------------------------------------------------
0ld course
Chemical Reactions -key concepts student guide 4 weeks duration Name__

Online component of the test

  1. You will need to log on here- remember to include your class name in the first field with your first name eg 10DEbony
  2. You will be given a second component of the test which has some valencies and other questions. this needs to be completed and returned to your teacher
  3. the test link is http://www.classroomclipboard.com/490625/Home/Test/fde75e13371bf7402da4138d996348a2#/InitializeTest.xaml
  4. the access code is LYX7MV

Key Concept
Vocabulary
Assessment
  1. The properties and structure of materials in terms of their constituent particles and forces holding them together.
  2. Construct and use atomic symbols and balanced equations to summarise chemical equations eg; neutralization, precipitation and combustion.
  3. The sustainable management of a resource.
  4. Chemical change in terms of energy.
mixtures
compounds
elements
solutions
solvent
solute
bonding: ionic, metallic, covalent
physical and chemical change
reactants and products
conservation of matter
rate of reaction
catalyst
yield
enzymes
formula
hydrocarbons
homologous
alkanes
alkenes
alkynes
functional group
combustion
neutralisation
precipitation
biodegradable
pressure
temperature
molecule
atom
electron
proton
anion/cation
Practical write up – student choice from pracs listed in suggested activities
Research report – student choice from research listed in extension & variation
Test
Done @ School
Teacher Signs
Done @ Home
Teacher signs
Priority 1
Suggested Activities
Extension and Variation
2.1: Matter – Revision - (very fast) states of matter, elements, compounds, mixtures, solutions.
Bonding – metallic, ionic and covalent (review fast)
Physical and chemical change (review fast)
Conservation of mass (review fast)
Balancing and writing Chemical equations (review fast)
Types of Reactions: neutralisation, combustion and precipitation
Questions: 1-4 (p56), sheet
Prac: Study of a reaction (p58)
Activity: Ionic formulas sheet

Homework Book: 2.1 Writing Formulas (p24-25)/2.1 Ionic compounds p16-17 (DIM BK3)

Go here for a Valency table and a step by step process of how to balance equations. Courtesy of Mr Warden.

Also a good animation and simulation on how balancing really works from Colorado Uni

Prac: Precipitation Reactions (sheet)
Homework Book: 2.2 Chem and Phys Change (p18-19)(DIM BK3)
Prac: Conservation of mass (p58)
Questions: 10-13(p56)
Homework Book: 2.3 Classifying reaction types (p20) (DIM BK3)/
2.2 Revising chemical equations (p26)
Homework Book: 2.3 and 2.4 (p28-31)
Online test for valency Access Key is
8C7F remember to type your class in front of your first name

Balancing more equations
It would help you to write out these equations as you work out the answers.

Practice balancing equations - here is a game where you fill in the blanks
http://www.sciencegeek.net/Chemistry/taters/EquationBalancing.htm

Here is another game to play balancing the equations
http://www.files.chem.vt.edu/RVGS/ACT/notes/scripts/bal_eq1.html

This one is a bit harder - read the instructions carefully - it would help you to write out the equation as you do these
http://www.syvum.com/cgi/online/fillin.cgi/squizzes/chem/baleq1.tdf?0
Investigate: Find out more about ionic, metallic and covalent bonding (p57)
Questions: More balancing equations (sheet)
Science at Work: Maths in Chemistry (p59)
Balancing equations 4 worksheets with answers.


2.2 Rate and Yield – investigating how experimental conditions affect how fast a reaction proceeds and how much products are made
Prac: calculating the rate of reaction (p69)
Questions: 1-3 (p67)
Prac: Effect of concentration, surface area, temp and catalyst on reaction rate (exps p 70-71)
Questions: 4-13 (p68)
Research Assignment: The commercial production of a chemical of importance.
Homework: 2.7 rates of reaction (p.38- 39)
Surfing: Companion website – assessing risk(p68)
Research: how do air bags work (p.69)


2.3 Organic Chemistry – investigating the properties, types and reactions of compounds classified as organic.
(alkanes, alkenes, and alcohols)
Investigate: Types of organic compounds and their bonding (p.72-75) - name and draw alkanes (methane to decane)
name and draw alkenes (ethene to pentene)
name and draw alcohols (methanol to butanol)
Prac: Making barrier cream (sheet)
Questions: 2-15 ( p77)
Homework Book: 2.8 Organic Chemistry (p.40)
Surfing: Companion website: find the role of bubble caps in fractional distillation (p.78)
Research: Different types of everyday Organic Chemicals


2.4: Green Chemistry – understanding the environmental concerns related to the commercial production of chemicals.
Revision
Test
Investigate: The principles of Green Chemistry
Questions: 1-14 (p.82)
Prac: Exploring the biodegradability of plastic (p.83)
Surfing: The history of Green Chemistry (p.83)
Analysing: Find a media article on a biodegradable product (p.83)


Revision and test preparation
Text Book: Chapter review p 84 questions 1 to 20


Revision sheet - bring your laptops to complete the online component of the test.












Class Notes

The law of conservation of matter (mass)

This states that matter can not be created nor destroyed. In chemistry this means that when we observe a reaction the elements present at the start of the reaction will also be present at the end of the reaction.

In our experiment we added calcium carbonate to hydrochloric acid in a closed conical flask while it sat on an electronic balance.
We knew a reaction happened because we saw - bubbles, balloons full of gas and the marble chip (calcium carbonate) got smaller.

The mass at the beginning of the reaction was
The mass after the reaction was ___

Why were the masses different?

It was expected to be the same. Any difference may be due to the electronic balance being left on for a long period of time and losing accuracy.

How this relates to equations of reactions.
The elements in the reactants should be in the same quantity in the product.

This means if our equation shows 1 calcium atom on the reactant side it should have one calcium on the product side. If it does not we have to go through a process called balancing the equations.

The reaction for this experiment is


CaCO3 + 2 HCl ----> CaCl2 + H2O + CO2 This is an example of a carbonate plus an acid reaction

Big number at the front of a element or compound means to multiply all the elements in the compound by that number.

A little number behind a letter means you multiply that letter (element) by that number to work out how many atoms of that element are in the reaction.
For more information on how to balance equations go here AND GO HERE FOR AN ANIMATION

Types of reactions
neutralisation reactions
This is when an acid is added to a base. These two compounds neutralise each other and form a salt and water
General form: Acid + Base -----> Salt + Water
Example; Hydrochloric acid + sodium hydroxide -------> sodium chloride + water
HCl + NaOH -------> NaCl + H2O

Examples of acids:

hydrochloric acid HCl
Sulfuric acid H2SO4
Nitric acid HNO3
Vinegar or Citric acid CH3COOH

Examples of bases

Sodium Hydroxide NaOH
Calcium Hydroxide Ca(OH)2
Magnesium Hydroxide Mg(OH)2
metal hydroxide

Practice
Write a balanced equation for sodium hydroxide + Nitric Acid [Hint write the word equation first]
,Write equations for
  1. Mg(OH)2 +H2SO4
  2. Mg(OH)2 +HNO3
  3. NaOH + H2SO4

Combustion Reactions

Combustion reactions is when oxygen is combined with another compound or element. We call this combining burning.
Common example is methane + oxygen ------> Carbon dioxide + water
CH 4 + O2 ----> CO2 + H2O

Precipitation

solution + solution ----> solid + solution

Rates of Reaction

Rate refers to the how fast the reaction reaches completion. The expt with the sodium thiosulphate and hydrochloric acid reached completion when all the liquid turned a milky yellow.

This expt showed the effect of concentration on the rate of the reaction.
Paste your graph you made using excel into your notes.
In conclusion the higher the concentration the ___ the reaction.

Size of the particles in a reaction affects the surface area that is exposed to react. For example 10g of calcium carbonate crushed as powder will result in very small particles. These will have a larger surface area when compared to a 10g stone of calcium carbonate (marble)

How did we test this?
To ensure it was a fair test we USed same amount of acid and the same mass of calcium carbonate.
The powder was faster because - it has the largest surface area - it would spread out over the desk the furthest. The rock would not spread out.

Does Temperature affect the reaction rate?
Describe the way we tested this question- list your ideas in point form.
1. we measured the temp of the sodium thiosulfate
2. added the acid and timed until the cross disappeared
3. we repeated steps 1 and 2 but we increased the temp of the sodium thiosulphate by sitting it in a water bath until its temp increased 10C from the time before
4. we did this 4 times.

Graph these results
Temp deg C
Time in Seconds
15
33
25
13
35
6
45
4

The reason the reaction was faster is because hotter the chemicals the faster the particles move. When particles are moving fast they are more likely to hit each other. Hence they will react.

Rates of reaction and catalysts

A catalyst is a chemical that can speed up a reaction but is not used up in the reaction
Expt
Prac 5 P 71
Aim: To describe the effect of a catalyst
Method
1. 10 Ml of H2O2 (hydrogen peroxide) in beaker A and in beaker B - Beaker A will be the control
2. Add small amount of Manganese dioxide MnO2 to beaker B- record observations
3. To Beaker C Add 10Mls of H2O2 and then Add 5 drops of NaOH and 10 Drops of KI-

Results
Observation
Beaker A small bubbles of oxygen
Beaker B lots of bubbles of oxygen- vigorous reaction
Beaker C cancelled
Conclusion Manganese dioxide was a catalyst that made the reaction rate increase (more bubbles) but did not seem to change itself- it was still a black powder.

Carbon Chemistry

Carbon chemistry's other name is organic chemistry. It is chemistry of living things and as such it usually only involves the elements - Carbon, Hydrogen and Oxygen ( Nitrogen too in some cases). This means water is an organic compound as is Natural gas - Methane.

The simplest organic chemicals are the hydrocarbons.
Hydrocarbons with single bonds between the Carbons are called ALKANES.
Hydrocarbons with a double bond between one of the carbons are called ALKENES
Hydrocarbons with triple bonds between a pair of carbons are called ALKyNES

The rules
Each carbon atom must have 4 bonds. These bonds are shown as straight lines coming off the letter C - this C represents 1 carbon atom.
On the other end of each stick must be a C or a H ( for hydrogen atom)
Each H can only have 1 stick coming off it.

The Code
The prefix of a word indicates the number of carbon attoms.
meth = 1, eth = 2, prop = 3 but = 4, pent = 5, hex = 6, hept = 7, oct = 8, non = 9, dec = 10

eg propane = means 3 carbon atoms joined by a single bond between the carbons
eg heptane = means 7 carbon atoms joined by a single bond between the carbon atoms
eg butene = means 4 carbons one double bond between 2 of the carbons

Alcohols
The alcohols are not hydrocabons as they have oxygen added to them. We say an hydroxy group has been added to the end of a alkane (or other) chain. The hydroxy group is called the functional group and is denoted in the naming convention by the letters "ol"

eg ethanol = this means 2 carbons in the chain joined by single bonds with an OH group on the end.

Ways to make alcohols naturally include fermentation. We do this when we make beer or wine or whiskey.
There are some problems with making your own alcohol they include increasing the number of impurities in the brew that leads to a higher than required alcohol content or alcohols that are very poisonous.
Eg Methanol - very poisonous - sends you blind
Propanol - very poisonous dissolves cells.
Ethanol is the alcohol in drinks.

A note about fermentation
this is an organic reaction
Glucose -----> carbon dioxide + alcohol