Emergetics Flashcards

1
Q

What are exothermic reactions

A

Reactions that transfer energy to its surroundings

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2
Q

What is the defenutiom of an endothermic reaction

A

A reaction that takes in energy from its surroundings

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3
Q

What is the effects of exothermic reactions on surroundings temperature

A

Surrounding temperature increases

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4
Q

What is the effects of endothermic reaction on the surroundings

A

Surrounding temperature decreases

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5
Q

Examples of exothermic reactions

A
  • combustion
  • respiration
  • neutralisation
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6
Q

Examples of endothermic reactions

A
  • photosynthesis
  • thermal decomposition
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7
Q

Why are certain chemical reactions used to heal wounds

A

Endothermic reactions can help absorb all of the heat from the wound

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8
Q

How to work out the energy change in reactions

A

E = MC(change in time)

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9
Q

Why would calculated values of energy change be different from the actual energy change

A

The energy could escape as heat, causing the calculated value to be higher than the real value

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10
Q

What is activation energy

A

The amount of energy that must be supplied to the reactants in other for the reaction to start

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11
Q

What is bond energy

A

Bond energy is the energy needed to break one mole of a particular bond

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12
Q

What type of reactions are breaking and making bonds

A

-Breaking bonds are endothermic, as energy is needed to overcome the existing forces between the Atoms in the molecule
-making bonds are exothermic, as energy is released when atoms move to a new, more stable form

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13
Q

What is bond energy measured in

A

kJ/mol

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14
Q

How to find bond energy

A

Energy in - energy out

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15
Q

When you get bond energy, and it is a negative number, what does it mean

A

That the reaction is exothermic, as it gives out energy and in turn looses its own energy

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16
Q

What is an oxidising agent

A

The one that gives oxygen to the other/ the one that gets reduced

Mg + CuO —> MgO + Cu

Copper is the oxidising agent as it initially has oxygen before the reaction

17
Q

What is the reducing agent (in terms of oxygen)

A

It is the one which gains oxygen

Mg + CuO —> MgO + Cu

Mg is the reducing agent as it initially does not have oxygen before the reaction

18
Q

What is an exothermic reaction in terms of energy

A

When more energy is released than is absorbed

19
Q

What is an exothermic reaction in terms of energy

A

An exothermic reaction is when more energy is released to the surroundings than is absorbed by the reactions