Download PHS 112 Test 5 Review Chapters 16

PHS 112
Test 5 Review
Chapters 16-17
A compound contains atoms of more than one element
bonded together to form a one substance. A mixture involves more than one substance blended
together but still separate substances (not bonded).
What is a saturated solution? A solution that cannot dissolve more solute.
Each circle represents an atom. Which of the following boxes contains an element? C
A compound? B
A mixture? A
What is the difference between a compound and a mixture?
How is the solubility of a solid affected by an increase in temperature?
Solubility of solids usually increases with temperature.
What is the easiest way for you to separate a mixture of sand and salt?
A) with tweezers and a magnifying glass
B) just add water
C) heat the mixture until one of the components melts
What do chicken noodle soup and garden soil have in common?
A) They are both examples of heterogeneous mixtures.
B) They both contain elements.
C) They are both examples of compounds.
In a solution made from one teaspoon of sugar and one liter of water, which is the solute?
A) sugar
B) water C) the teaspoon
D) both sugar and water
Which of the following describes the term concentration?
A) It is what you are doing now to answer this question. B) It is the amount of solute in a given amount of solution. C) It is the amount of
solvent in a given amount of solution.
D) It is the given amount of solvent per amount of solute.
Which of the following solutions is the most dilute?
A) one liter of water with 1 gram of sugar
B) one liter of water with 2
grams of sugar
C) one liter of water with 5 grams of sugar
D) one liter of water with 10 grams of sugar
Which of the following pictures might best describe a soap or detergent?
A) a B) b
C) c
D) d
Which of the following statements does not describes the similarity between soaps and
detergents?
A) They have a polar ionic end and a long nonpolar tail.
B) Both dissolve oils.
C) Both are synthetic.
D) Both are biodegradable.
E) Both are made from fatty acids.
What is the purpose of treating water with chlorine gas or ozone during water purification?
A) to kill bacteria B) to improve taste
C) to improve color D) to remove solids
E) none of the above
Which of the following statements about desalinization is untrue?
A) You can use osmosis to remove salt from saltwater.
B) You can
use distillation to separate salt from saltwater.
C) Desalinization is an energy intensive process.
Does the concentration of chlorine in drinking water tend to increase or decrease as it leaves the water treatment plant and disperses into the
community? Why?
A) Increases. As the chlorine reacts with the bacteria in the water, more chlorine is produced.
B) Increases. As the water evaporates the chlorine concentration would increase in the remaining water.
C) Decreases. Evaporative processes and reaction with organic bacteria would decrease the chlorine concentration.
Osmosis involves this substance passing through a membrane. Water
Is this equation balanced? 3Al (s) + 3 Br2 (l) → Al2Br3 (s) No
What is wrong with the following depiction of a chemical reaction?
A) These boxes contain only molecules but no atoms. B) One box contains more molecules than the other.
C) One box contains more atoms than the other.
Given the following generic chemical reaction, which is the product? Y
X→Y
The energy needed to get a reaction started. An energy barrier to reaction.
How is activation energy affected by a catalyst? A catalyst lowers the activation energy. Less energy is required
to get over the energy barrier.
Based on these energy diagrams, which has the largest activation energy? d
Which reactions are exothermic? a and b
What is the activation energy?
R = reactants P = products
What can you deduce about the activation energy of a reaction that takes billions of years to go to completion? How about a reaction that
takes only fractions of a second? A) The activation energy of both these reactions must be very low.
B) The activation energy of both these reactions must be very high.
C) The slow reaction must have a high activation energy while the fast reaction must have a low activation energy.
D) The slow reaction must have a low activation energy while the fast reaction must have a high activation energy
Which of the following statements about catalysts is NOT true?
A) A catalyst alters the rate of a chemical reaction.
B) A catalyst can be consumed in a reaction as long as it is regenerated. C) A catalyst can be used to speed up slow reactions.
D) A catalyst does not change the energy of the reactants or the products. E) All of the above are true.
A catalytic converter increases the amount of carbon dioxide emitted by an automobile. Is this good news or bad news? A) bad news because
carbon dioxide contributes to global warming
B) good news because plants thrive on carbon dioxide
C) bad news because
the carbon dioxide contributes to acid rain D) good news because it means more noxious chemicals are not being emitted
What is an endothermic reaction? A) It is a reaction that requires heat as a reactant.
B) It is a reaction where the products have more
All are true
energy than the reactants. C) It is a reaction where there is a net adsorption of energy from a reaction.
Use the bond energies below to determine whether the following reaction is exothermic or endothermic:
H2 + Cl2 → 2 HCl
H-H (bond energy: 436 kJ/mol) Cl-Cl (bond energy: 243 kJ/mol)
H-Cl (bond energy: 431 kJ/mol)
A) Exothermic with more than 50 kJ of energy released. 436+243-(2x431)= -183kJ B) Endothermic with more than 50 kJ of
energy absorbed. C) Exothermic with less than 50 kJ of energy released. D) Endothermic with less than 50 kJ of energy absorbed.
Which of the following statements best describes the concept of entropy?
A) Energy has a tendency to disperse. B) Energy is neither
created nor destroyed. C) The entropy of the universe is constantly decreasing.
D) The energy released in a chemical reaction is the
same as the difference in the energy of the bonds broken and formed.
E) Energy has a tendency to remain in one place.
T(T/F) Salad dressing is a heterogeneous mixture.
F(T/F)
T(T/F)
Orange juice is a pure substance.
Any juice is a mixture. (water, vitamin C, flavors)
Reverse osmosis can be used to purify water.