Exam Style Questions Flashcards
What 3 properties would be suitable for use as an insulator inside electrical transformers?
- non-flammable so it does not burn
- does not conduct electricity so can insulate
- extremely un-reactive so it does not react to materials inside the transformer
What is an ore?
rock that consist of metals which can be extracted for economic gain
Why do ions move to the positive electrode?
negatively charged ions are attracted to the anode
Why do alkaline batteries eventually stop working?
a reactant is used up
What gas is produced at the negative electrode?
hydrogen
Why can alkaline batteries not be charged?
the reaction is reversible
Advantages and Disadvantages of Hydrogen Fuel Cells
Fuels cells do not need electronically recharging
Hydrogen is very flammable and explosive
No pollutants are produced, the only waste product is water
The hydrogen produced for the fuel cell can be produced from non-renewable resources
They can be made into different sizes for different uses
Hydrogen is very difficult to store, due to being a gas at room temperature and explosive
How could students find the total mass of copper produced?
- filter the mixture
- wash and dry copper
- weigh copper collected
- add to the increase the mass of the electrode
Suggest how the oxygen removes most of the carbon from the molten iron?
oxygen reacts with the carbon from the molten iron and produced carbon dioxide
Give one use of a fullerene?
deliver drugs inside the body
Explain why the reactivity of elements changes going down Group 1?
outer shell of electrons gets further away from the nucleus so there is less attraction between the electrons and nucleus so the electron is more easily lost
Suggest 2 improvements to the titration experiment?
- place a white tile under the conical flask to see the colour change
- add acid solution drop wise to the endpoint
Why is it important to warm the acid in crystallisation?
increase rate of reaction
Why is it important to filter the mixture?
remove excess of unreacted copper oxide
Explain the trends in the boiling points of halogens?
as you down the column, the boiling pint increases as the molecular mass increases so the intermolecular forces increase which requires a lot of energy to overcome.