Unit A Energy and Matter in Chemical Change : Section 3.0 Flashcards

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1
Q

What are the elements on the left side of the equation called?

A

Reactants

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2
Q

What are the elements on the right side of an equation called?

A

Products

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3
Q

What are indications of chemical reactions?

A
  • Formation of gas
  • Formation of solids
  • Energy Changes
  • Change in odour
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4
Q

What is happening during an explosion? What are the states of matter? How is the volume affected?

A

A small amount of a solid or liquid converts quickly to a large volume of gas

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5
Q

What is the chemical formula for methane?

A

CH4

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6
Q

What is an example of a commercial use for an explosion?

A

Airbags

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7
Q

What is five-minute epoxy?

A

A product that contains 2 chemicals that when mixed hardens in 5 minutes

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8
Q

How does 5 minute epoxy work?

A

The molecules have several places where they can join causing it to form one large molecule

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9
Q

What state are metal elements always in?

A

Solid

Except mercury Hg is liquid

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10
Q

What state are all the diatomic elements?

A

They are all gases with exceptions:

Br2 is liquid at room temperature since the melting point is -7.2 degrees Celsius and room temperature is above that at 25 degrees celsius, so it is not a solid. In addition, the boiling point of Br2 is 58.8 degrees Celsius, so it is not a gas at room temperature since room temperature is lower than it’s boiling point.

I2 is either liquid or solid in chemical equations. At room temperature it is solid since it does not melt until 113.7 degrees celcius. 113.7 degrees Celsius is melting point. 184.3 degrees celcius is the boiling point.

Hydrogen, nitrogen, oxygen, fluorine, and chlorine are all gases at room temperature. As such, they are called diatomic gases or elemental gases.Bromine is typically a liquid at room temperature, and iodine is solid (but can be liquid depending on several factors)

Some other elements can form diatomic molecules, but the bonds are very weak and unstable. They don’t stay diatomic for long.

Only the seven diatomic elements form strong bonds and appear in this form almost always

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11
Q

What are diatomic elements?

A

Elements that come in pairs such as O2

Use polyatomic for more than two such as Se8

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12
Q

What state does bromine come in?

A

Liquid

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13
Q

What state does Iodine come in?

A

Solid

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14
Q

What do letters in subscript within brackets indicate in a chemical equation?

A

The state of an element

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15
Q

What does a subscript of (aq) mean?

A

It is dissolved in water

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16
Q

What state are all ionic compounds?

A

Solid

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17
Q

When is an ionic compound shown as aqueous?

A

When it is very soluble and dissolved in water. Use the solubility chart to look up if it is soluble in water. If it is very soluble then it will be marked as aqueous providing that water is actually there during the experiment.

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18
Q

When is an ionic compound shown as solid?

A

When it is only slightly soluble even if it’s in water

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19
Q

How do you predict the state of molecular compounds?

A

The smaller the molecules means most likely gas. The bigger the molecules most likely solid

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20
Q

What are exothermic reactions?

A

When chemical reactions releases energy in the form of heat, light, or electricity

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21
Q

How do car batteries work? What are the chemicals involved?

A

They contain sulfuric acid (H2SO4(aq)) which is a strong electrolyte which reacts with solid lead (Pb(s)) and lead (IV) oxide (PbO2(s)) to produce electricity.

The products of this reaction are lead(II) sulfate in solution and water

PbO2 is solid, dark brown, has a crystalline structure, and is insoluble in water.

This is an example of an acid and a metal reacting. It is also an example of a double replacement reaction and thus it must be occurring in solution since all double replacement reactions must occur in solution. It is a neutralization reaction as well since an acid is a reactant and a salt and water are produced.

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22
Q

What is a combustion reaction?

A

When oxygen reacts with a substance to form a new substance and gives off energy.

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23
Q

How is electricity made using combustion?

A

Coal is burned and the steam used to burn the coal is able to turn a turbine. Then the turning motion can operate a generator creating electricity.

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24
Q

What is a reactant in a combustion reaction?

A

Oxygen

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25
Q

What are the products of a combustion reaction?

A

Carbon dioxide (or element dioxide), energy, and water vapor

26
Q

What are the fossil fuels?

A

Coal, Oil, and natural gas

27
Q

What is gasoline made out of?

A

Hexane C6H14

28
Q

What are endothermic reactions?

A

Reactions that absorb energy

29
Q

What are biochemical reactions essential to?

A

Life

30
Q

What are catalysts?

A

Chemicals that speed up a reaction but are not used up by it

31
Q

What are biochemical reactions?

A

Reactions that happen at an organism’s body temperature and are sped up by catalysts

32
Q

What type of reaction is synthesis? Is it endothermic or exothermic?

A

Bringing two or more atoms together.

Endothermic

Photosynthesis is a synthesis reaction

33
Q

If energy is on the left side of chemical reaction is it endothermic or exothermic?

A

Endothermic

34
Q

If energy is on the right side of a reaction is it exothermic or endothermic?

A

Exothermic

35
Q

What type of reaction is cellular respiration?

A

Exothermic

36
Q

What are the characteristics of chemical reactions?

A
  • Production of new substances
  • Flow of energy
  • Change of state (but not solely a traditional phase change, just it happens due to the properties of the new substance or because something heated up or cooled down as a result of a chemical reaction)
  • Consistent with the law of conservation of mass
37
Q

What comes along with a formation of a new substance?

A

New properties of state, melting point, color, density

38
Q

How can the flow of energy be detected?

A

-A change in temperature during the reaction

39
Q

What is the law of conservation of mass?

A

States that in a chemical reaction matter cannot be created or destroyed

40
Q

What does the arrow mean when writing a chemical formula?

A

Produces

41
Q

What is a formula equation?

A

Uses the chemical formulas of the reactants and products in a chemical reaction

42
Q

What is a skeletal equation?

A

A formula that shows the different elements but not in the correct proportions

43
Q

What are coefficients?

A

Numbers placed in front of elements or compounds to put in proper proportions

44
Q

What are the 5 common types of chemical reactions?

A
  • Formation reactions
  • Decomposition reactions
  • Hydrocarbon combustions
  • Single replacement
  • Double replacement
45
Q

What is another name for a formation reaction?

A

Synthesis

46
Q

What takes place in a formation reaction?

A

2 elements combine to form a compound

47
Q

What is a decomposition reaction?

A

When a compound is broken down into its different parts. Only 1 reactant

48
Q

What are hydrocarbons?

A

Substances that contain hydrogen and carbon

49
Q

What is hydrocarbon combustion?

A

When hydrogen and carbon mix with oxygen and burn producing carbon dioxide and water vapor

50
Q

What is the chemical formula for natural gas?

A

There isn’t one formula since natural gas is not a pure substance. However, CH4 (methane) is the primary constituent of natural gas

Some ethane, propane, as well as heavier hydrocarbons, water, carbon dioxide, nitrogen, hydrogen sulfide

51
Q

What is a single replacement reaction?

A

When a reactive element reacts with an ionic compound. After the reaction, the element ends up in a compound and an element ends up by itself

52
Q

What is a double replacement reaction?

A

When 2 ionic compounds switch elements

53
Q

What kind of chemical reaction can only take place in a solution?

A

Double replacement reactions

54
Q

What is the mole?

A

The unit mole is the measure chemists use to measure the quantity of elements

1 mol = avogadro’s constant amount of particles

55
Q

What is the number of particles in one mole called?

A

Avogadro’s number

56
Q

What element do chemists use to define the mole?

A

Carbon-12

57
Q

What number is Avagadro’s number?

A

6.02 x 10^23

58
Q

What is the formula for finding the atomic molar mass?

A

M = m/n

m = nM

M molar mass found on the periodic table

m actual mass in the experiment

n actual moles in the experiment

59
Q

What does m mean when finding the atomic molar mass?

A

The mass in grams

60
Q

What does n mean when finding the atomic molar mass?

A

The number of moles

61
Q

What does M mean when finding the atomic molar mass?

A

The molar mass,

find it on the periodic table

62
Q

All about combustion reactions

A