Chapter 8,9,10 Test

Question 1

Solution

Answer 1

a homogenous mixture of 2 or more substances

the particles are of molecular size

Question 2

Solvent

Answer 2

part of the solution which does the dissolving

most common types is water (aqueous solution)

Question 3

Solute

Answer 3

part of the solution which is dissolved

Question 4

Calculating a Solution: STEPS

Answer 4

1. Determine n = Cx V

2. Determine m = n x M

Question 5

Preparing a Solution: STEPS

Answer 5

1. Use an electronic balance to obtain the desired mass of solute
2. Transfer all of the solute to the volumetric flask
3. Add water until the flask is about half full. Then swirl the flask to dissolve the solid in the water completely
4. Fill the flask by adding water slowly and carefully, using a wash bottle, until the bottom of the meniscus just touches the etched line on the flask
5. Stopper the flask and mix it by inverting it several times.

Question 6

Calculating a Dilution: STEPS

Answer 6

1. Determine the dilution factor
2. Determine the amount of solvent needed using the dilution formula
   c1v1 = c2v2
3. Plug in the known quantities da solve

Question 7

Preparing a Dilution: STEPS

Answer 7

1. Add about 10 or 20 mL of water to a volumetric flask and set it aside
2. Start with a clean, dry pipette that can measure the needed volume of solution. Squeeze the pipette bulb and place it over the pipette
3. Rinse the pipette with the solution to be measured
4. a) Squeeze the bulb again and then place the tip into the solution to be measured
   b) Fill the pipette until it is beyond the line indicating the desired volume
5. Remove the bulb and quickly and smoothly seal the top of the pipette with your finger or thumb. Remove pipette from solution
6. Carefully release your finger allowing just enough liquid to escape so that the meniscus is at the graduation mark of the desired volume
7. a) Keep your finger tightly over the pipette and transfer the tip to the volumetric flask
   b) Touch the tip of the pipette against the side of the flask and allow the solution to flow into the flask
8. a) Fill the volumetric flask to the graduated line with water
   b) Stopper the flask and mix the solution by inverting the flask several times
   c) Check the volume reading after mixing and add more water if needed

Question 8

Ionic Equation

Answer 8

equations in which soluble compounds that dissociate are written as ions

Question 9

Net Ionic Equation

Answer 9

equations in which only substances which take part in the reaction are written

Question 10

Spectator Ions

Answer 10

Ions that don’t participate in the reaction

Question 11

Arrhenius Theory

Answer 11

Acid: any substance that dissociates to form Hydrogen in an aqueous solution

Base: any substance that dissociates to form OH in an aqueous solution

Question 12

Bronstead-Lowry Theory

Answer 12

Acid: any substance from which a proton may be removed

Base: any substance that
removes a proton from an acid

Question 13

Problems with A’s theory

Answer 13

water remains unchanged in the equation for the dissociation of hydrochloric acid in water. However, since H2O is a polar molecule, the H ion attaches itself to awater molecule forming a HYDRONIUM ION, H30+

Question 14

Conjugate Acid

Answer 14

the particle that results when the base receives the proton from the acid

Question 15

Conjugate Base

Answer 15

the particle that remains when a proton is removed from the acid

Question 16

Conjugate Acid-Base

Answer 16

2 molecules or ions that are related by the transfer of a proton proton transfer

Question 17

Strong Acid

Answer 17

an acid that dissociates completely into ions in water

the concentration of hydronium ions in a dilute solution of a strong acid = concentration of the acid

Question 18

Weak Acid

Answer 18

an acid that dissociates very slightly in a water solution

the concentration of hydronium ions in a solution of a weak acid is always less than the concentration of the dissolved acid

Question 19

Strong Base

Answer 19

dissociates completely into ions in water

oxides and hydroxides of alkali and alkali earth metals

Question 20

Weak Base

Answer 20

dissociates very slightly in a water solution

Question 21

Titration

Answer 21

the concentration of 1 solution is determined by quantitatively observing its reaction with a solution of known concentration

Question 22

Standard Solution

Answer 22

the solution of the known concentration

Question 23

Equivalence Point

Answer 23

the point at which the number of moles of added solution is stoichiometrically equal to the original number of moles of the standard solution; neutralization is complete.

Question 24

End-Point

Answer 24

a physical observation that tells us that the equivalence point has
been reached.

Question 25

Titration Steps

Answer 25

1. a pipette is used to measure a precise volume of standard solution into a flask.
2. let the flask rest under a burette that contains the the solution of the unknown concentration
3. after adding a few drops of indicator, take an initial burette reading
4. Start adding the known solution, slowly into the flask
5. the end-point of the titration occurs when the indicator changes colour

Question 26

Dissolving

Answer 26

is when a solute breaks down its composition into molecules when it is added to / combined with a solvent.

Question 27

Solubility

Answer 27

is the amount of solute that dissolves in a given quantity of solvent, at a certain temperature.