Forensic Science with Criminology

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What is an isotope?
Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons.
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What is the Heisenberg Uncertainty Principle?
It is impossible to define with absolute precision the position and momentum of an electron at the same instant.
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What are the four quantum numbers?
1. Principal Quantum Number. 2. Angular Momentum Quantum Number. 3. Magnetic Quantum Number. 4. Spin Quantum Number.
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What is used to represent the principal quantum number and what does it describe?
Principal quantum number is represented by the letter (n). It is used to describe the shells. The higher the value of n, the higher the potential energy associated with the shell. The further away from the nucleus the electron is likely to be found.
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What is used to represent the angular momentum quantum number and what does it describe?
The angular momentum quantum number is represented by the letter (l). It is used to define the subshells which the shells are subdivided into.
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What values can l take?
l can take any values ranging from 0 to (n-1).
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What does each value of l relate to?
The orbital shape.
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What is used to represent the magnetic quantum number, and what does it describe?
The magnetic quantum number is represented by the letters ml. It is used to describe the multiplicity and spatial orientation of the orbitals.
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What is multiplicity?
How many orbitals there are of the same shape.
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What is spatial orientation?
The direction the orbitals are facing.
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For each value of l, what values can ml take on?
-l to l.
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What is used to represent the spin quantum number and what is it used to describe?
The spin quantum number is represented by the letters ms, and describes the electron's direction of spin.
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For each set of n, l, ml combinations, what 2 values can ms take on?
+1/2 and -1/2.
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What is the Aufbau Principle?
The electrons will fill the lowest energy orbitals first.
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What is the Pauli Principle?
No two electrons can have the same set of four quantum numbers.
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What is Hund's Rule?
In degenerate orbitals, electrons have the same spin.
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What is electronegativity?
The power of an atom to attract electrons to itself.
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What is electronegativity represented by?
X.
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What is the Octet Rule?
Atoms with full "valence" (outer) shells, are most stable.
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What is covalent bonding?
Atoms share to satisfy the octet rule.
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What are cations?
Positively charged ions.
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What are anions?
Negatively charged ions.
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What is ionic bonding?
Electrons are transferred between atoms to satisfy the octet rule.
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What do oppositely charged ions do?
Attract.
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TOPIC 2
BALANCING EQUATION
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What is the law of the conservation of mass?
Total mass of reactants = total mass of products.
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Balance this equation: NaCl + BeF2 --> NaF + BeCl2
2NaCl + BeF2 --> 2NaF BeCl2
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TOPIC 3
EQUILIBRIA
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What is equilibria?
In principle, all chemical reactions occur in equilibrium (a closed system).
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What is a system?
The thing that is being studied, contained within a boundary.
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What are the surroundings?
Everything else in contact with the system.
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What is an open system?
Energy and matter can transfer between system and surroundings.
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What is a closed system?
Only energy can transfer between system and surroundings, matter cannot.
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What is an isolated system?
Neither energy nor matter can transfer between system and surroundings.
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What happens with reactions in a closed system?
They occur in both the forward and reverse direction to some extent, until an equilibrium is reached.
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What are the five key characteristics of an equilibrium state?
1. dynamic. 2. closed system. 3. concentrations remain constant. 4. no change in macroscopic properties. 5. equilibrium independent of starting point.
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What is the equilibrium constant?
aA + bB <-----> cC + dD
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What is Kp?
It is the equilibrium constant calculated from partial pressure.
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What is Kd?
Dissociation constant.
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What is Ka?
Acidity constant.
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What is Le Chatelier's Principle?
States that a system in equilibrium has it's conditions changed, then the position of the equilibrium will move to counteract the change.
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What effect will increasing the concentration have on a reaction?
Increasing the concentration of reactants will push the reaction towards the products until equilibrium is restored. The reverse is also true if we increase the concentration of products.
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What effect will increasing the pressure have on a reaction?
If we increase the pressure of a reaction, by decreasing the volume, the change is counteracted by decreasing the total number of molecules.
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What is an endothermic reaction?
Reactions that take in heat from the surroundings.
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What is an exothermic reaction?
Reactions that give heat out to the surroundings.
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What effect will increasing the temperature have on a reaction in equilibrium?
The equilibrium will shift to favour an exothermic reaction (give heat out to surroundings).
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What effect will decreasing the temperature have on a reaction in equilibrium?
The equilibrium will shift to favour an endothermic reaction (taking heat in from surroundings).
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What are catalysts?
Catalysts are enzymes that increase the rate of a reaction by lowering the required activation energy for said reaction to take place.
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What are buffers?
They help keep pH levels within a desired range. They are generally weak acids or alkalines.
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TOPIC 4
MOLES AND MOLAR RATIO
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What is relative atomic mass?
The mass of an atom relative to hydrogen.
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What is a mole?
The amount of substance that contains the same number of elementary particles as 12 g of Carbon.
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What is Avagadro's Constant?
6.022 x 10(23) mol-1
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What are elementary particles?
Molecules, atoms, or ions.
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How many moles are in 18g of water, H2O?
H=1 x 2 = 2 and O= 16 so 16+2=18. 18/18= 1. Therefore the answer is 1 mole.
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Other cards in this set

Card 2

Front

What is the Heisenberg Uncertainty Principle?

Back

It is impossible to define with absolute precision the position and momentum of an electron at the same instant.

Card 3

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What are the four quantum numbers?

Back

Preview of the front of card 3

Card 4

Front

What is used to represent the principal quantum number and what does it describe?

Back

Preview of the front of card 4

Card 5

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What is used to represent the angular momentum quantum number and what does it describe?

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