| What to measurements ca be taken in order to determine the rate of reaction? | The amount of reactant used up per unit of time
The amount of product produced per unit of time |
| How can steepness of graph be used to determine the rate of reaction? | The steeper the graph the faster the rate of reaction |
| How can a graph be used to determine if a reaction has ended? | When the graph is flat the reaction is over |
| Give three ways the rate of a reaction could be increased | Increasing the temperature
Increasing the Concentration
Increasing the surface area |
| Use the collision theory to explain why the rate of reaction increases when concentration increases | When it is more concentrated it is more likely for the particles to collide successfully, therefore more successful collisions, as a result greater rate of reaction. |
| Use the collision theory to explain why the rate of reaction decreases over time | Since there are less reactant particles, lower concentration hence lower chances of successful collisions, therefore lower successful collisions, as result lower rate of reaction. |
| Use the collision theory to explain why the rate of reaction increases when temperature is increased | When temperature increases, particles gain energy which make them move faster, therefore collide more frequently as well as with greater energy, hence greater chances of successful collisions, hence more successful collisions, as a result greater rate of reaction. |
| Use the collision theory to explain why the rate of reaction increases when surface are increases | When surface area increases, more of the reactant particles are exposed, hence greater chance of collisions, therefore higher chances of successful collisions, as a result rate of reaction increases |
| What is a catalyst? | A catalyst is a substance that speeds up a chemical reaction, but remains chemically unchanged |
| What is an enzyme? | An enzyme is a protein made by cells to act as biological catalyst |
| Give three examples of catalysts and where they are used | Manganese (IV) oxide- Catalyses the decomposition of Hydrogen peroxide
Iron - Used in the manufacture of Ammonia
Vanadium (IV) oxide - Used in the manufacture of sulfuric acid |
| What enzyme is used in liver to break down Hydrogen peroxide? | Catalase |
| Where can enzymes be used? | In making biological detergents |
| What is the best conditions for an enzyme? | Optimum temperature
Optimum pH |
| What is the catalyst in Photosynthesis? | Chlorophyll |
| How can the rate of a photochemical reaction be increased? | By increasing the intensity of light |
| How do the indicators: Litmus, Methyl orange and Phenolphthalein change color to acids? | Litmus: red
Methyl orange: red
Phenolphthalein: Colorless |
| How do the indicators: Litmus, Methyl orange and Phenolphthalein change color to alkali? | Litmus: Blue
Methyl orange: yellow
Phenolphthalein: pink |
| How does universal indicator change color according to different pH levelss | Strong acids: Red
Weak acids: Yellow
Neutral: Green
Weak alkali: Blue
Strong alkali: Violet/Purple |
| How can you differentiate between an alkali and acid using its chemical formula? | Acids will have H+(Hydrogen) ions while alkali will have OH- (Hydroxide) ions |
| What are the differences between an weak acid and strong and strong acids? | Strong acids
-High conductivity
-Lower pH
-High concentration of hydrogen ions
- Completely dissociates when dissolved in water(Aqueous solution)
Weak acids
-Low conductivity
-Higher pH
-Low concentration of hydrogen ions
-Partially dissociates when dissolved in water(Aqueous solution) |
| What are the differences between Strong alkali and weak alkali? | Strong alkali
-High conductivity
-High pH
-High concentration of Hydroxide ions
-Completely dissociates when dissolved in water(Aqueous solution)
Weak Alkali
-Low conductivity
-Low pH
-Low concentration of Hydroxide ions
-Partially dissociates when dissolved in water(Aqueous solution) |
| What are the products formed when ...
1) Acid reacts with a metal
2) Acid reacts with a base
3) Acid reacts with a carbonate | 1) Salt + Hydrogen
2) Salt + Water
3) Salt + Water + Carbon Dioxide |
| What are the products formed when...
Bases such as Sodium, Potassium, Calcium Hydroxides react with Ammonium salts | Salt + Water + Ammonia |
| Give one place where neutralization is helpful | If soil is too acidic Lime can be used to neutralize the acid |
| Why is metal + acid not a neutralization reaction? | Since the oxidation state of the metal changes it is a redox reaction |
| What is the ionic reaction for neutralization reactions? | H+(aq) + OH-(aq)----> H2O(l) |
| Acids are proton_______ and Bases are proton_______ | Donors
Accpetors |
| Basic oxides belong to the larger group of compounds called _____ | Bases |
| What type of oxides are formed when non metals react with oxygen? | Acidic oxides |
| What is a amphoteric oxide? | It is an oxide which reacts with acids and alkali |
| Give two examples of amphoteric oxides. | Aluminium oxide
Zinc oxide |
| What are neutral oxides ? | Oxides that do not react with acids and alkali |
| What are the steps to prepare a salt starting with a metal? | 1) Add the metal to an acid, it starts to dissolve and hydrogen bubbles off. Bubbling stops when all the acid is used up.
2)Some zinc is still (the zinc was in excess) Remove it by filtering. This leaves an aqueous solution of zinc sulfate
3)Heat the solution to evaporation some water, to obtain a saturated solutions. Leave this to cool, crystals of zinc sulfate appear. |
| What are the steps to prepare a salt starting with an insoluble ? | 1) You should start with the metal oxide(or even metal carbonate). Add some metal oxide to acid It will dissolve on warming. Keep adding metal oxide until no more can dissolve
2)Which means all the acid has been used up, remove the excess solid by filtering.
3) Heat the solution then leave it to cool, crystals of salt forms |
| What are the steps to prepare a salt starting with an alkali(titration)? | 1) Put alkali into a flask using a pipette, add two drops of phenolphthalein.
2) Add the acid from the burette just a little at a time, swirl the flask carefully to help the acid and alkali mix.
3)Once the indicator turns colorless all the alkali has been used up so no more acid should be added.
4) Use the burette to find how much acid was added to neutralize the alkali.
5) Now repeat the without the indicator(it would be an impurity) , use the same volume of alkali then add the right volume of acid required to neutralize the alkali.
6) Heat the solution from the flask to evaporate the water, crystals of the salt will be left behind |
| Which salts are all soluble in water ? | Sodium, Potassium and Ammonium salts |
| Which nitrates are insoluble in water ? | All nitrates are soluble in water |
| Which chlorides are insoluble in water ? | Silver and lead chloride |
| Which sulfates are insoluble in water ? | Lead, Calcium and Barium Sulfate |
| How do you make an insoluble salt using precipitation? | You must mix a solution that contains its positive ion with one that contains its negative ions |
