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Unit 1 Practice Questions

Questions 1-4 refer to the following:

(A) Volume(B) Temperature(C) Density(D) Pressure(E) Mass

1. Is a quantity that allows one to calculate mass if density is known

2. Always varies with the number of molecules present in a sample of a particular substance

3. Can be expressed as kilograms per liter4. Is a measure of the average kinetic energy of a

substance’s molecules

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Questions 1-3 refer to the following:

(A) The rule is to add concentrated acid to water slowly(B) The rule is to add water to concentrated acid slowly(C) Carefully replace unused or excess chemicals into

their properly labeled containers from which they came

(D) Flush eyes with water at the eyewash fountain for at least 15 minutes

(E) Dispose of chemicals in the proper places and following posted procedures. Do not return them to their original containers

1. The proper way to dilute a concentrated acid2. How to properly dispose of chemicals not needed3. What to do if a chemical splatters into your eyes

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Questions 1-4 refer to the following:

(A) Density(B) A solid(C) Volume(D) Weight(E) Matter

1. Gives the mass per unit volume2. Has mass and a definite size and shape3. Gives the space occupied4. Has mass and occupies space

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Questions 1-2 refer to the following:

(A) A molecule(B) A mixture of compounds(C) An isotope(D) An isomer(E) An acid salt

1. The simplest unit of water that retains its properties

2. A commercial cake mix

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I

If the density of a solid substance and its volume are both known, mass can be calculated

II

For any substance, the relationship between the mass and volume varies directly with sample size

For any substance, solid, liquid or gas, mass increases as volume increases

Density represents mass per volume

BECAUSE

BECAUSE

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I

A substance composed of two or more elements chemically combined is called a mixture

II

The properties of the constituents of a mixture are retained

A chemical change involves change in the composition and molecular structure of the reactants

In a chemical reaction bonds are broken and new substances are formed

BECAUSE

BECAUSE

7

I

The burning of paper is a physical change

II

When a chemical change occurs energy is either gained or lost by the reactants

Propane can be decomposed chemically

Propane is a compound made up of simpler elements

BECAUSE

BECAUSE

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I

Methane is defined as a compound

II

Methane can be broken down chemically

1,100 grams is equal to 1.100 kilograms

To convert grams to kilograms one must divide by 100

BECAUSE

BECAUSE

9

I

It is possible to separate a water-soluble salt from a water-insoluble substance

II

The water-soluble substance will be caught in the filter paper, while the insoluble substance passes through filter paper

When diluting an acid, the acid is added to water

The dilution of concentrated acid can release heat

BECAUSE

BECAUSE

10

I

The density of a sample of water is doubled by doubling its mass

II

Compared to a gas, the molecules in a liquid are relatively far apart

Iron is an element It cannot be broken into smaller units and retain its physical and chemical properties

BECAUSE

BECAUSE

11

Two solid objects are of equal volume, but object A has density = X, and object B has density = (0.5)X.Which of the following is true concerning objects A and B?

(A) Objects A and B are of equal density(B) Object B has twice the density of object A(C) Objects A and B are of equal mass(D) Object A has one half the mass of object B(E) Object A has twice the mass of object B

12

The prefix centi- means

(A) One thousand(B) One thousandth(C) One hundred(D) One hundredth(E) One millionth

13

A substance that can be further simplified by ordinary chemical means may be which of the following?

I. An element or a compoundII. A mixture or a compoundIII. An element or a mixture

(A) I only(B) II only(C) III only(D) I and II only(E) I , II, and III

14

Which of the following would you not do in a laboratory setting?

I. Pour acids and bases over a sinkII. Wear gogglesIII. Heat a stoppered test tube

(A) I only(B) II only(C) III only(D) I and III only(E) I , II, and III

15

A student conducted an experiment and obtained three values during three repetitive trials: 1.65, 1.68, 1.71. Later, the student discovered that the true value was 2.37. In contrast to the real value, the experimental results should be characterized as:

(A) Not accurate and not precise(B) Accurate but not precise(C) Not accurate but precise(D) Accurate and precise(E) Accurate, precise, but unreliable

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Which of the following is considered to be a dangerous procedure in the laboratory setting?

(A) Pouring all liquids, especially acids and bases, over the sink

(B) Wearing goggles(C) Pushing glass tubing, thermometers, or glass

thistle tubes through a rubber cork(D) Pointing the mouth of a test tube that is being

heated away from you and others(E) Knowing where the fire extinguisher and eye-

wash stations are located

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The following statements were recorded while preparing carbon dioxide gas in the laboratory. Which one involves an interpretation of the data rather than an observation?

(A) No liquid was transferred from the reaction bottle to the beaker.

(B) The quantity of solid minerals decreased.(C) The cloudiness in the last bottle of limewater was

caused by the product of the reaction of the colorless gas and the limewater.

(D) The bubbles of gas rising from the mineral remained colorless throughout the experiment.

(E) There was a 4oC rise in temperature in the reaction vessel during the experiment.

18

The property of matter that is independent of its surrounding conditions and position is

(A) Volume(B) Density(C) Mass(D) Weight(E) State

19

Which substance can be decomposed chemically?

(A) Ammonia(B) Iron(C) Neon(D) Hydrogen(E) Fluorine

20

A book is lifted off the floor and placed on a table that is one meter above the floor. The book has

(A) Gained sound energy(B) Lost chemical energy(C) Gained potential energy(D) Gained kinetic energy(E) Lost nuclear energy

21

Which statement is incorrect regarding energy?

(A) Energy can be given off in a reaction(B) Energy can be gained in a reaction(C) Energy cannot be created or destroyed(D) Energy can take various forms(E) Energy has mass and takes up space

22

Which type of change is different from the other four?

(A) Baking a potato(B) Rusting of an iron nail(C) Burning a piece of paper(D) Melting an ice cube(E) Ignition of propane

23

Which of the following is not a physical property?

(A) Color(B) Phase(C) Odor(D) Boiling point(E) Reactivity with oxygen

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Which substance cannot be decomposed chemically?

(A) Ammonia(B) Tellurium(C) Methane(D) Water(E) Lunch

25

Which sample represents a homogeneous mixture?

(A) CH3OH (l)

(B) CH3OH (aq)

(C) CH3OH (g)

(D) CH3OH (s)

(E) None of the above

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All of the following involve a chemical change EXCEPT

(A) The formation of HCl from H2 and Cl2

(B) The color change when NO is exposed to air(C) The formation of steam from burning H2 and O2

(D) The solidification of vegetable oil at low temperatures

(E) The odor of NH3 when NH4Cl is rubbed together with Ca(OH)2 powder

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Which sample is a homogeneous mixture?

(A) KI (aq)

(B) Fe (s)

(C) CO2 (g)

(D) NH3 (l)

(E) NaCl (s)

28

A student took a melting point of an organic compound four times. His work produced the following results: 97oC, 99oC, 100oC and 97oC. If the real melting point of the compound is 88oC, then his results can be summarized as

(A) Both accurate and precise(B) Neither accurate not precise(C) Accurate but not precise(D) Precise but not accurate(E) extrapolated

29

In the metric system, the prefix kilo- means

(A) 100

(B) 10-1

(C) 10-2

(D) 102

(E) 103

30

All of the following are compounds EXCEPT

(A) Copper sulfate(B) Carbon dioxide(C) Washing soda(D) Air(E) lime

31

An example of a physical property is

(A) Rusting(B) Decay(C) Souring(D) Low melting point(E) High heat of formation