Paper Based Questions Flashcards
1
Q
Write an equation ions formed when calcium oxide reacts with water
A
CaO+H2O
—–>Ca(2+) +2OH(-)
2
Q
How to determine whether a silver halide is iodide or bromide?
A
- Add concentrated aqeuous ammonia
- Silver bromide is soluble
- Silver iodine is insoluble
3
Q
Three Marks
Explain, in terms of electrons, why chlorine is more reactive than bromine
A
- Attraction between outer electrons and positive nucleus decreases
- Chlorine atoms are smaller than bromine atoms
- Chlorine gains an electron more readily than bromine
4
Q
Six Marks
Describe + Explain imbs present in methanol,methanal and methane and deduce their relative boiling points
A
- Methanol~hydorgen bonding polar O-H bond
- Methanal~PD-PD polar C=O bond
- Methane~ID-ID movement of electrons within one molecule induces a dipole in adjacent molecule
- Strength of imbs HB>pd-pd>id-id
- Boiling points methanol>methanal>methane
- All compounds have id-id
5
Q
Two marks
Suggest and explain why magnesium can replace calcium in carbonate shell
A
- Mg and Ca both in group two-both can react with carbonate
- So same number of outer shell electrons
6
Q
Three Marks
Describe + Explain the conditions necessary for nuclear fusion to occur
A
- High temperature
- High pressure
- Provides large enough kinetic energy to overcome the repulsion by the positive charge of the nuclei
7
Q
Three marks
Give one advantage and two disadvantages of using coal as an energy source compared to ‘cleaner’ fossil fuels
A
- Advantage~large supply
- Disadvantage~can cause respiratory problems and smog
8
Q
Two marks
Explain why CH3Cl has a permananent dipole
A
- The molecule is asymetrical
- So the charges the charges don’t cancel each other out