Unit 3 - Solutions Flashcards Preview

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Flashcards in Unit 3 - Solutions Deck (68):
1

What are pure substances

Type of matter that has a definitive mixed composition ... Like elements and compounds

2

What are mixtures

Combinations of matte that can be separated by physical means and do not have definite proportions

3

Heterogeneous mixtures (mechanical mixtures)

Mixtures that the different components are visible

4

What are solutions

Homogeneous mixtures which have uniform composition and the different components are not visible

5

How to seperate homogenous mixtures

Distil water
Filter

6

What are solutions made of

At least one substance dissolved in another

7

What is a solvent

The dissolver ... Usually the larger quantity (like the water in salt water)

8

What is the solute

What is dissolved in the solvent (the salt in salt water)

9

Both solvents and solutes can be

Solids, liquids or gases

10

What's an aqueous solution

Any solution in which water is the solvent

11

What is the universal solvent

Water; water dissolves a lot of solutes because of its unique properties

12

How can toxins in the earth go through the food chain

The bottom of the food chain may not be affected because the levels are so low once reached but organisms at the top of the food chains can end up with toxic levels of these chemicals

13

What is concentration

The amount of solute relative to the amount of the solvent

14

What is diluted

Low solute (salt), high solvent (water)

15

What is concentrated

High solute (salt), low solvent (water)

16

How can concentration be expressed

Ppm, ppb, % mass, % volume, mol/L, mmol/L, mg/dL, %

mol/L is what we use

17

What's mol/L

Concentration

18

Molarity

Number of moles of solute per litre of solvent

19

The concentration equations

C=n/v

N=m/M

20

Standard solution

Solution of known concentration

21

Two ways to make a solution

Dissolve a measured amount of pure solute in a certain volume of solvent

Solute a standard solution

22

How to prepare a solution of known concentration from a solid solute

Calculate the mass of the solute required to achieve a specific concentration and volume
1) measure _g of _solute
2)dissolve solute in _mL of water
3)transfer solution to a _mL flask
4)fill flask to _mL and mix by inverting

23

What is matter

Any solid, liquid or gas that has a mass and volume

24

Describe how to prepare 100mL of a 0.0800 mol/L solution in KMnO4(aq)
MEMORIZE THIS

1) measure out 1.29g of KMnO4(s)
2) dissolve the KMnO4(s) in 50 mL of distilled H2O
3) transfer the solution to a 100mL volumetric flask
4) fill to 100mL and invert to mix

25

How can you make a less concentrated solution

Out of a solution of known concentration by diluting it

26

What is dilution

Decreasing the concentration of a solution by adding more solvent (water)
... The number of moles stays constant

27

Dilution equation

V1C1=VFCF

V1 is always smaller than Vf
C1 is always bigger than Cf

28

Dissolving is a _____ change

Physical

29

The molecules or ions of a solid solute are held together by

Bonds

30

When dissolving occurs the bonds of molecules or ions of a solid solute ____

Break

31

3 processes involved in dissolving

1) bonds broken of solute (dissolved) ... Endothermic (absorbs energy... Cold)
2) bonds broken of solvent (dissolver)... Endothermic (absorbs energy, cold)
3. Bonds form between solutes and solvents (exothermic... Releases heat... Energy)

32

Endothermic

Needs energy, energy absorbed, is cold

33

Exothermic

Releases energy, gives off heat

34

If more energy is released than required, the overall dissolving process is

Exothermic

35

If less energy is released than is required , the overall dissolving process is

Endothermic

36

What are electrolytes

Aqueous solutions that conduct electricity

37

What are non electrolytes

Aqueous solutions that do not conduct electricity

38

What's dissociation

Occurs when ionic compounds break apart into their ions when they are dissolved in an aqueous solution

39

What are dissociation equations

Are used to show what happens to a substance when it is put into water

40

The 4 situations in dissociation equations

1) insoluble ionic or molecular compounds
2) soluble ionic compounds
3) soluble molecular compounds
4) acids

41

Dissociation: insoluble ionic or molecular compounds

Don't dissolve using the solubility chart for ionic compounds

42

Dissociation equations: soluble ionic compounds

Dissolved to form ions in solution, ionic bonds are broken. Use the solubility table
Balance the number of ions

43

Dissociation equations: soluble molecular compounds

Dissolve to form molecules in solution
Intermolecular forces are broken

44

Dissociation equations: acids

Molecular compounds, they're polar , dissolve to form ions in solution , balance the number of ions

45

Anions

Negative ions

46

Cations

Positive ions

47

The types of net ionic equations

1) non-ionic equations
2) total ionic equations
3) net ionic equations

48

Non ionic equations

Shows all reactants and products as if they didn't dissociate in solution

49

Total ionic equations

This type of equation is more accurate and shows all soluble reactants and products dissociated into ions

50

Net ionic equations

This type of equation shows only the chemical changes that occurs
Spectator ions are cancelled

51

Spectator ions

Ions that don't change in the net ion reaction and are canceled

52

Qualitative analysis

Is a process used to identify the presence of specific substances in solution

53

Quantitive analysis

Identifies the amount of particular substances

54

Flame tests

Many metals produce a distinctive colour of flame when they are heated

55

Precipitation reaction

A double replacement reaction in which a solid product is formed (the precipitate)
You can add a known solution to an unknown solution to see if a precipitate forms

56

The solubility of a solute

Is the amount a solute that dissolved in a given quantity of solvent at a given temperature

57

And unsaturated solution

Is a solution that does not have the maximum amount of solute dissolved in it

58

A saturated solution

Is a solution that contains the maximum amount of a dissolved solute at a given temperature

59

Supersaturated solution

Contains more dissolved solute than its solubility

60

The degree to which a solute is soluble depends on

The strength of attraction between
1) the solute particles
2) the solute particles and the solvent particles

61

Solutes can be

Insoluble; less than 0.1
Slightly soluble; 0.1-1
Soluble; 1+

62

Once a solute dissolves it appears that the solute-solvent bonds

Break

63

When you study a saturated solution the amount (mass of moles) of u dissolved solute at the bottom

Remains unchanged

64

Over time I dissolved particles become dissolved and dissolved particles

Crystallize

65

A saturated solution is said to be in a state of

Equilibrium

66

Equilibrium occurs when

A process (dissolving) and the reverse process (crystallization) take place at the same rate

67

What is used to show equilibrium

The double arrow

68

QUESTIONS TO ASK YORSELF WHEN DOING THE WORK

1) is the molecule ionic, molecular a base or an acid
2) is it soluble (research molecular)
Bases and acids are
Ionic use the chart
3) if it's soluble its (aq) if not it stays the same
4) will it create ions? Ionic; yes, acids and bases; yes, molecular; no
5) if not only the aq changes