Additional Chemistry Questions

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  • Created by: Moonisah
  • Created on: 01-06-12 13:50
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Moonisah Mirza
Additional Chemistry Questions
1. What is the electric configuration of sodium, magnesium, carbon and oxygen?
Sodium- 2.8.1 Magnesium- 2.8.2 Carbon-2.4 Oxygen-2.6
2. What is the difference between covalent bonding and ionic bonding?
Ionic Bonds:
Ionic bonds are bonds that are formed between two atoms, usually a metal and a non-metal
through losing or gaining an electron. The metal loses one or more electrons and the
non-metal gains one or more electrons. What this does is it makes "ions" ions are atoms that
are charged because they gained or lost an electron. These ions have a positive (for the
metal) or negative (for the non-metal) charge and because of that they attract to each other
and form the ionic bond.
Covalent Bonds:
Covalent bonds are usually between two non-metals. Covalent bonds involve atoms that
SHARE electrons, these atoms do not lose or gain electrons but instead will share them to
gain a full outer energy level. By sharing electrons each atom pulls on them and the atoms
form a bond through the electron sharing known as the covalent bond.
3. Show the bonding in potassium iodide?
4. Show the bonding of ammonia(NH3) , hydrogen (H2) water(H20), oxygen (O2)
hydrogen chloride (HCL) methane (CH3) chlorine (CL2)
AMMONIA WATER OXYGEN
HYDROGEN HYDROGEN CHLORIDE METHANE CHLORINE
Particle =Relative Change
Proton =+1
Neutron =0
Electron =-1
5. Draw an atom and label each part and the charges on the particles

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6. What does the atomic number of the atom represent?
The number of protons that an atom has is its atomic number.
7. What does the mass number of the atom represent?
We call the number of protons and neutrons in an atom its mass number.
8. In an atom which is the lowest energy level, and which is the highest energy level?
The innermost shell - or lowest energy level - is filled first.…read more

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16. What is a macromolecule?
A macromolecule is a molecule containing a very large number of atoms.
17. Give examples of giant covalent structures.
18. What does delocalised mean?
The term 'delocalised' refers to an electron which is not 'attached' to a particular atom. For
example, in metals, some of the outer electrons are delocalised and are free to move
around the whole metal solid. This is why metals conduct electricity.
19. Describe an ionic lattice.…read more

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Diamond
Graphite
23. Show the bonding in silicon dioxide.
24. Why do metals conduct electricity?
Metals conduct electricity because the seas of delocalized electrons are free to move about
and they carry a negative charge. An electric current give the electrons energy to move.
25. Graphite is pure carbon, it is a non metal; so why does is conduct electricity?
Graphite's structure forces one electron to leave each carbon atom.…read more

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29. What is the formula mass/ molecular mass Mr of the following compounds FE2O3 ,
CaCO3, NH3.
FE2O3- 160. CaCO3-100 NH3-17
30. What is a mole?
31. What percentage of C is there inCO2?
27%
32. REVISE HOW TO WORK OUT EMPERICAL FORMULAE.…read more

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37. Why is it not always possible to obtain the calculated theoretical yield of product?
It is very rare to get 100% of percentage yield; this is because some of the product or
reactant is converted into waste or gets lost along the way.
38. What is atom economy?
The atom economy of a chemical reaction is a measure of the amount of starting materials
that become useful products.
39.…read more

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44. Why are these conditions chosen?
In the Haber process, the forward reaction is exothermic, it prefers low temperatures. But at
low temperatures the reaction is slower. On the other hand higher yields of ammonia are
produced at higher pressures, however high pressures are dangerous to work with and are
expensive. So a compromise is made; a reasonably high temperature makes the reaction
faster and the catalyst speeds up the reaction.
45.…read more

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The 4 basic ways are
Temperature : increasing temperature increases molecular activity
Concentration : a concentrated solution will have more interaction
Surface Area : a larger surface means more reactants come in contact
Catalysts: catalysts speed the eventual result.
Stirring - mixing the reactants so that more of the reactants come in contact for a
given concentration, and products are moved out of the way
51.…read more

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61. What happens to the yield of a reversible reaction if it is exothermic in the forward
reaction and the temperature is increased?
The percentage yield is decreased.
62. What happens to the yield if the temperature is decreased?
The yield of product is increased.
63. If the pressure is increased in a gaseous reaction that is reversible, what happens?
The amount of yield also increases.
64.…read more

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When we pass an electrical current through brine we get three products. chlorine gas is
produced at the positive electrode, hydrogen gas is made at the negative electrode, and a
solution of sodium hydroxide is also formed.
70. Why is this reaction important in industry?
Chlorine is used to kill microbes in drinking water and swimming pools. Hydrogen is used to
make margarine and hydrochloric acid. Sodium hydroxide is used to make bleach, paper and
soap.
71.…read more

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