Chapter #1 (States of Matter)

Question 1

What are the six changes of states?

Answer 1

(s)-(l) = melting
(l)-(g) = evaporating/boiling
(g)-(l) = condensing
(s)-(g) = depositing
(g)-(s) = Subliming

Question 2

what is an atom?

Answer 2

Smallest unit of matter which retains its properties.

Question 3

What is a molecule?

Answer 3

A small group of atoms.

Question 4

What is a ion?

Answer 4

Charged atoms or molecules.

Question 5

What is an element?

Answer 5

Substance made of one type of atom.

Question 6

What is a compound?

Answer 6

Substance made of two or more types of atoms that are chemically bonded.

Question 7

What is a mixture?

Answer 7

Substance made of two or more types of atoms that are NOT chemically bonded.

Question 8

How are the particles in a solid moving?

Answer 8

The particles are vibrating.

Question 9

How are the particles in a liquid moving?

Answer 9

The particles are sliding over each other.

Question 10

How are the particles in a gas moving?

Answer 10

The particles are moving in random, straight lines.

Question 11

How strong are the forces in a sloid and how is the the density in a solid?

Answer 11

The forces in a solid are strong and the density is high.

Question 12

How strong are the forces in a liquid and how is the the density in a liquid?

Answer 12

The forces in a liquid are strong and the density is high.

Question 13

How strong are the forces in a gas and how is the the density in a gas?

Answer 13

The forces in a gas are weak and there is low density in a gas.

Question 14

What are the differences between physical and chemical changes?

Answer 14

Physical: The arrangement of the particles changes and it is easily reversible. the substance is the same just rearranged.

Chemical: the bonding changes and it is irreversible. New substance is made

Question 15

What is the definition of soluble?

Answer 15

A substance that can dissolve.

Question 16

What is the definition of insoluble?

Answer 16

A substance that can’t dissolve.

Question 17

What is the definition of solute?

Answer 17

The substance that dissolves (normally a solid).

Question 18

What is the definition of solvent?

Answer 18

The substance that the solute dissolves in (normally a liquid).

Question 19

What is the definition of saturated?

Answer 19

A mixture in which no more solute can dissolve.

Question 20

What is the definition of solution?

Answer 20

A mixture of solvent and solute.

Question 21

What is the definition of suspension?

Answer 21

An insoluble solid in a liquid.

Question 22

What is the definition of dissociate?

Answer 22

Particles separate (no longer touching).

Question 23

How is solubility measured?

Answer 23

g/100cm^3

Question 24

Does temp. affect solubility (of solids) and if so, in what way?

Answer 24

Yes, in solids the higher the temp. the higher the solubility, This is because the forces are weaker the higher the temp. So it is easier for them to dissociate.

Question 25

Does temp. affect solubility (of gases) and if so, in what way?

Answer 25

Yes, the higher the temp. the lower the solubility of gases. This is because as the temp. is increased the particles spread even farther apart.

Question 26

When do you use filtration to separate mixtures.

Answer 26

To separate an insoluble solid in a liquid (supension)

Question 27

What is the filtrate?

Answer 27

The liquid collected from filtering a mixture.

Question 28

What is the residue?

Answer 28

The solid on the filter paper.

Question 29

When do you use crystallization to separate a mixture?

Answer 29

When you want to separate a solute from a solvent.

Question 30

What is a method to measure solubility?

Answer 30

1. Record mass of conical flask (144.10g) 2. Measure 25.0cm3 of water into a flask 3. Re-record the mass (168.26g) 4. Add excess solid and leave to dissolve 5. Use water bath to maintain temp. to dissolve. 6. Filter mixture (problem: water remains on filter paper.) 7. re-record mass of solution. 8. Calculate solubility using volume of water. (175g - 168.26g = 6.74g)

Question 31

What is distillation?

Answer 31

It is a method to separate ANY solid from a liquid. but if solid is insoluble it is much easier to use filtration. When the solid is soluble and the solvent is required, we use simple distillation. Distillation can also be used if two liquids are mixed together. This is called fractional distillation.

Question 32

What are the two requirements needed for fractional distillation?

Answer 32

1. Miscible - One liquid mixed together. 2. Liquids have different boiling points.

Question 33

What is the steps for distillation?

Answer 33

1. solution evaporates A (with higher bpt) other solution does not evaporate as insufficient (not enough) energy is applied. 2. Solution A particles enter junction enter junction. Temp =bpt of 1st liquid. Some of the particles lose energy and go back down, but most are in junction 3. In the water tube...solution A particles lose energy. they slow down and start to slide over each other. spread out, not touching to touching. 4. process continues until all solution A particles are separated.

Question 34

What is a way to separate soluble solids with the same bpt and different solubilities.

Answer 34

using chromatography.

Question 35

What is the method for chromatography?

Answer 35

1. Place aprox. 2cm of solvent in a beaker. 2. draw a PENCIL line aprox. 2.5 cm from bottom of chromatography paper (base line). 3. Place one drop of mixture on base line. 4. Stand paper in solvent and cover beaker (solvent moves upwards bcs it is attracted to paper. 5. leave until solvent is aprox 1cm from top 6. Draw pencil line to show distance of solvent (solvent front). 7. Dry paper with hot plate.

Question 36

Why do the particles of the components (solute(mixture wanted to separate)) separate)

Answer 36

The particles of the components separate due to the difference in attraction to solvent particles. If there is a stronger attraction the substance is more soluble.

Question 37

How do you calculate the Rf (retention factor)

Answer 37

Rf = distance of component/distance of solvent Then compare to lit value.

Question 38

What is a method to separate immiscible liquids?

Answer 38

Using a separating funnel.