Question | Answer |
At room temperature and normal atmospheric pressure, one mole of any gas occupies what volume, and why? | 24dm^3, because Avogadro’s law states that one mole of any gas will occupy the same volume under a particular temperature and pressure |
What equation allows you to work out the amount (number of moles) of a gas, and how is this transferred at RTP (room temperature and pressure)? | Amount of gas = volume of gas/gas molar volume
So at RTP, amount of gas = volume of gas/24 |
What volume of chlorine is needed to react with 1.12kg of iron? 2Fe (s) + 3Cl2 (g) -> 2FeCl3 (s) | 720 dm^3 |
What are fertilisers and what do they contain? | Fertilisers are substances that are sprayed on crops - they contain soluble nitrogen compounds which are needed by plants to make proteins, used for growth |
What are some examples of natural and man-made fertilisers? | Natural fertilisers = manure, guano
Artificial fertilisers = nitrogenous fertilisers manufactured from ammonia |
What are the advantages and disadvantages of using nitrogenous fertilisers? | Advantage of artificial fertilisers: more crops are grown so more people are fed
Disadvantage of artificial fertilisers: eutrophication - rain, lakes, algal blooms, lack of sunlight, dead plants, fungi and bacteria, lack of oxygen, dead fish |
What is dynamic equilibrium? | A reaction reaches dynamic equilibrium when the forwards and backwards reactions occur at the same rate, so the amount of each substance in the equilibrium is constant |
What is the effect of temperature on the position of equilibrium? | A higher temperature increases the yield of the product in the endothermic direction. A higher temperature increases the rate of reaction (collision theory). A higher temperature is more expensive so there are financial constraints |
What is the effect of pressure on the position of equilibrium for gaseous reactions? | A higher pressure increases the yield of the side with fewer gas moles. A higher pressure increases the rate of reaction (collision theory). A higher pressure is more expensive and is difficult to produce and maintain |
What is the effect of concentration on the position of equilibrium for solutions? | A higher concentration of reactants increases the yield of the product, and will increase the rate of reaction (collision theory) |
What is the effect of adding a catalyst on the position of equilibrium? | Catalysts do not change the yield. Catalysts increase the rate of reaction equally in both directions, allowing a reaction to be run at lower temperatures |
What is the Haber process (include word equation)? | The Haber process is an industrial process in which ammonia is produced in a reversible reaction from hydrogen and nitrogen. Nitrogen + hydrogen ⇌ ammonia |
Where are the elements required for the Haber process obtained from? | Nitrogen is extracted from the air and hydrogen is produced from methane, the main gas in natural gas |
Which reaction (forward or backward) is exothermic / endothermic? | The forward reaction is exothermic (releases heat) but the backward reaction is endothermic (takes in heat) |
What are the desirable conditions for the Haber process? | * High temperature (450ºC)- decreases the yeild of ammonia but increases rate of reaction (e->right)
* High pressure (200 x atmospheric pressure) - increases the yield of ammonia & increases the rate of reaction
* iron catalyst |
Why does the Haber process have to take place in giant vessel reactors? | There has to be strong walls that can withstand the high pressure |