Chapter 5 - Chemical Reactions

Rules for naming compounds with more than one polyatomic ion

1. Ending 'ate' and this ion contains oxygen 2. Ending 'ite' when there is one less oxygen than the 'ate' ion .

What are the rules for naming metal and non metal compounds ( 2 elements only)?

1. Metallic element always named first 2. Name of the non metal is shortened 3. The ending 'ide' is added to the shortened metal name

Example of Chemical Equations- Sodium Chloride:

1. Na Cl 2. +1 -1 3. Yes, equal 4. 1 : 1 5. Na2O.

Rules for naming compounds with 2 elements only (both non metals):

1. Name of the first element given in full like the periodic table 2. Starting of the name 'mon', 'di', 'tri' , 'treta' etc ; used to indicate how many atoms of the second element are in the molecule 3. If only 2 elements then name of the second is shortened and the ending 'ide' is used.

Steps to writing chemical formulas

1. Write the chemical symbol for each element 2.Write the charge for each ion 3. Are the charges numerically equal if not make them equal 4. Identify the ratio of ions 5. Write the formula.

Give an example of how catalysts increases rate of reaction

A catalytic converter in a car exhaust uses platinum metal as a catalyst and helps convert carbon monoxide to carbon dioxide.

What is respiration:

A chemical reaction that occurs inside the cells of living things .

What is an enzyme?

A natural occurring catalyst.

What is an acid?

A substance that produces hydrogen ions ( H+ ) when dissolved in water or opposites of bases.

What is a base?

A substance that produces hydroxide ions (OH-) when dissolved in water or opposites of acids .

What is the general equation for neutralisation reactions?

Acid + base --> salt + water

What is the general equation for acid and carbonate reactions?

Acid + carbonate --> salt + water + carbon dioxide

What is the general equation for acid and metal reactions?

Acid + metal --> salt and hydrogen

Explain how agitation increases the rate of reaction

Agitation ensures that the reactants are kept in contact by removing the build up of products around the reactants ; Stirring reactants can also increase the rate of reaction.

Give an example of how temperature increases rate of reaction

Baking a batch of biscuits, you place it in the oven to increase the rate of chemical reactions that convert the dough to biscuits.

Why does neutralisation occur when acids and bases mix together?

Because the hydrogen ions from the acid combine with the hydroxide ions from the base to form water (H2O) which is neutral.

What is an ionic bond?

Bond between metal and nonmetal ; The nonmetal attracts the electron, so it's like the metal donates its electron to it.

What is a covalent bond?

Bond between two nonmetals with similar electronegativities ;Atoms share electrons in their outer orbitals.

How are corrosion and combustion similar

Both involve the combination of metals with oxygen to form metal oxides Both are exothermic.

Chemical equation of respiration

C6H12O6 + 6O2 --> 6CO = 6H2O .

Give an example of decomposition reaction

Carbonic acid water + carbon dioxide .

What are catalysts?

Catalysts are chemicals which speed up chemical reactions but are not consumed (used up) during the reaction ; Can be considered 'chemical helpers' that help the reactants to form the products.

What are exothermic reactions

Chemical reactions that release energy in the form of heat or light; Release heat.

What do endothermic reactions feel like:

Cold because they absorb the heat eg;ice pack.

What is an example combination reaction?

Combination of hydrogen and chlorine to produce hydrochloric acid .

Define combustion reactions:

Combustion describes chemical reactions in which substances burn oxygen gas to make light and heat; Therefore they can also be classified as exothermic reactions.

What is the difference between combustion and corrosion

Corrosion is when a metal reacts with oxygen to produce a metal oxide but does not make significant amounts of heat whereas combustion is when a substance burns in oxygen gas to produce light and heat.

How are corrosion and combustion different:

Corrosion occurs much slower than combustion Even though both reactions produce big amounts of heat, corrosion heat production goes unnoticed because it's slow.

Explain how temperature increases the rate of reaction

Either increases speed of particles in the liquid and gases which causes particles to collide more frequently so more chemical reaction occurs Increased temperature gives particles more energy so when molecule collide they hit harder causing the reactants to rearrange more easily to form products because the chemical bonds are more likely to break.

What do exothermic reactions include:

Flames, explosions and fireworks.

How do chemical reactions happen?

For 2 particles to react they must collide first.

Give an example of how agitation increases rate of reaction

For example, if a solid piece of calcium carbonate is dropped into the bottom of a beaker of hydrochloric acid, it will react with acid to produce calcium chloride, water and carbon dioxide gas.

What is a precipitate?

Formed when 2 soluble reactants combine to form an insoluble product which is the precipitate.

Word equation of respiration

Glucose + oxygen --> carbon dioxide and water

Reaction between hydrochloric acid and magnesium metal produces large amounts of hydrogen gas ( H2) ; What is the balanced equation for this reaction: Name the type of reaction:

Hydrochloric acid + magnesium --> magnesium chloride + hydrogen gas 2HCl + Mg MgCl2 + H2. Acid and metal reaction

What is the equation for the combination of hydrogen and chlorine

Hydrogen gas + chlorine gas --> hydrochloride gas H2 + Cl2 --> 2HCl.

What does soluble mean?

If a substance dissolves.

What does it mean for a liquid or gas to be concentrated?

If there is a high amount of substance present in liquid or gas it is highly concentrated ; It is concentrated.

What does it mean or a liquid or gas to diluted?

If there is a low amount of substance present in a liquid or gas, it is lowly concentrated ; It is diluted.

What are polyatomic ions?

Ions containing more than one atoms.

What does respiration involve:

It involves the combination of glucose with oxygen to produce carbon dioxide and water

What are some combustion reaction examples:

Lighting a match Burning gas on a stove Burning coal in a power station Igniting fuel in car engine .

What is the general word equation for corrosion reactions

Metal + oxygen --> metal oxide

What substances undergo thermal decomposition when heated

Metal carbonates and metal hydrogen carbonates.

What is corrosion?

Most metals will combine with oxygen gas in the air to produce metal oxides which is a process known as corrosion.

How are new substances made during chemical reactions:

New substances are formed during chemical reactions by rearranging atoms rather than destroying them.

What are combination reactions:

Occurs when 2 reactions combine to form a single product .

How does precipitation occur?

Particles from 2 soluble compounds mix together and some stick together to form an insoluble solid. The solid precipitates out of the solution, making it murky; Usually then the solution clears as the precipitate then settles on the bottom.

What are cations?

Positive ions.

What are endothermic reactions:

Put heat in, absorb heat and energy.

Distinguish between reactants and products in a chemical reaction

Reactants are the initial substance of a chemical reaction whereas the product is produced by the chemical reaction.

How fast is respiration:

Respiration is slow compared to combustion so it doesn't produce explosive amounts of heat but it is fast enough to keep your body warm

What is a precipitation reaction?

Sometimes when 2 clear solutions mix they react to form an insoluble solid; The solid is said to precipitate (fall) out of the solid.

What are hydrocarbons:

Substances made of only hydrogen and carbon atoms Burn in oxygen to produce large amounts of energy Combustion of hydrocarbons produce carbon dioxide and water .

When sulfuric acid (H2SO4) reacts with calcium carbonate (CaCO3) to produce calcium sulfate ( CaSO4), water and carbon dioxide ; The balanced equation for this reaction is (Name the type of reaction):

Sulfuric acid + calcium carbonate --> calcium sulfate + water + carbon dioxide H2SO4 + CaCO3 CaSO4 + H2O + CO2 . Acid carbonate reaction

Explain how temperature concentration increases the rate of reaction

The amount of chemical in a certain volume of water Increasing the concentration of the reactants will increase the rate of the the reaction.

What does respiration do

The energy produced by respiration is used by the organism to live

Give an example of how enzymes increases rate of reaction

The initial process of digestion uses the enzyme amylase which is found in the saliva to break down carbs into simple sugars for easy absorption into the body.

What is salt?

The ions that the acid and base leave behind.

When can precipitation occur?

The scale that builds up in kettles, pipes and tape is sodium calcium carbonate that has precipitated out of the tap water.

What is activation energy?

The smallest amount of energy particles must have before they react.

What can classified as an alkaline solution?

The solution formed by hydroxide ions being dissolving water .

What forms can hydrocarbons be in

They can be in gas form such as methane (CH4), in liquid form such as octane in petrol (C8H18), or solid form such as candle wax ( C20H42).

Explain how catalysts increase the rate of reaction

They reduce the amount of energy that is required to convert the reactants into products They make it easier for reactant molecules to collide and form products.

How can you predict the formation of a precipitate as result of a chemical reaction?

Using the solubility rules table you can predict what will happen when 2 ionic solutions are mixed.

What is a decomposition reaction?

When a single reactant breaks apart to form several products .

When does a neutralisation reaction occur?

When an acid reacts with a base.

Examples of respiration

When exercising you respire more so you produce more heat.

How do particles undergo thermal decomposition:

When heated

What is thermal decomposition:

When substances only decompose when heated.

When do reactions take place?

When the particles that make up the reactants come together.

When does incomplete combustion occur

When the supply of air or oxygen is poor, water is still produced but carbon and carbon monoxide are produced instead of carbon dioxide.

What is the general equation for combination reactions:

X + Y --> XY.

What is the general equation for decomposition reactions

XY --> X + Y ,.

Give an example of how concentration increases rate of reaction

You concentrate the reactants whenever you turn up the gas knob on a heater or stove.

Exothermic

exo= means out.

What is the general equation for complete combustion:

hydrocarbon + oxygen → carbon dioxide + water.

What is the general equation for incomplete combustion

hydrocarbon + oxygen → carbon monoxide + carbon + water

What is complete combustion?

needs a plentiful supply of air so that the elements in the fuel react fully with oxygen.

What are anions?

negative ions

Fuels such as natural gas and petrol contain hydrocarbons. What happens when they hydrocarbons completely:

the carbon oxidises to carbon dioxide the hydrogen oxidises to water - (remember that water, H2O, is an oxide of hydrogen) .