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Name:______
CHEMISTRY 1211 Fall 2007
EXAM #1
This exam is 7 pages long. Please read through all of the questions first and ask about anything you do not understand. You will have one hour and 15 minutes to complete this exam. Exams will be picked up at the end of the class period. No late exams will be accepted!
You are allowed to use a calculator. If you do not have a calculator, setting up the problem correctly will gain you some points but you will not receive full credit for any question you do not answer completely.
Included in this exam is a periodic table, which should be stapled to the back of the exam.
CHEATING IS NOT ALLOWED. ANYONE CAUGHT CHEATING WILL BE TURNED OVER TO JUDICIAL AFFAIRS.
The exam is worth a total of 100 points. Each question is labeled with its exact point value. Be sure to answer all of the questions on the exam.
Good Luck!
1.) (5 points, 1 pt each) Label the following as either a chemical or a physical change.
a.) Souring of milk ______
b.) Melting of silver ______
c.) Digestion of food ______
d.) Condensation of steam ______
e.) Burning of coal ______
2.) (3 points) Matter is classified into three states. Which answer contains all of the following statements that are true and no false statements.
a.) The gaseous state of a substance is less dense than the liquid state
b.) Substances in the solid state are rigid and have definite shapes
c.) Substances in the liquid or gaseous state are easily compressed
d.) Substances in the gaseous state fill any container completely
e.) Substances in the liquid state assume the volume of the container.
a.) I, II and IV b.) I, II and V c.) I, II and III
d.) II, IV, and V e.) I and II
3.) (5 points, 1 point each) Label the following as a homogeneous mixture, heterogeneous mixture or pure substance.
a.) Sugar ______
b.) Gasoline ______
c.) An aqueous suspension of magnesium hydroxide ( milk of magnesia)
______
d.) Samples of nitrogen and oxygen in the same container
______
e.) Samples of argon and iron in the same container
______
4.) (3 points) Perform the indicated mathematical operations and round off the answer to the correct number of significant figures.
(12.67 x 4.23) ¸ 23.42 =
5.) (4 points) Which one of the following lists units of volume in increasing order i.e. from smallest to largest?
a.) microliter<kiloliter<centiliter<liter<milliliter
b.) milliliter< centiliter< microliter< kiloliter, liter
c.) centiliter< milliliter< liter< kiloliter< microliter
d.) microliter< milliliter< centiliter< liter< kiloliter
e.) milliliter< centiliter< liter< kiloliter< microliter
6.) (4 points) What is the mass of 6.50 cm3 of mercury? Its density is 13.6 g/mL.
7.) (4 points) Express 16.7 cubic feet in cubic centimeters.
8.) (4 points) Which one of the following is not true concerning cathode rays.
a.) They originate from the negative electrode
b.) They travel in straight line in the absence of electric or magnetic fields
c.) They impart a negative charge to metals exposed to them
d.) They are made up of electrons
e.) The characteristics of cathode rays depend on the material from which they are emitted.
9.) (4 points) What is the symbol for an atom composed of 35 protons, 44 neutrons and 36 electrons?
10.) (10 points, 2 pt each)Write the formula for the following:
a.) Lithium sulfide ______
b.) Zinc (II) hydroxide ______
c.) Silver (I) phosphate ______
d.) Magnesium bromide ______
e.) Cobalt (III) nitrate ______
11.) (10 points, 2 pt each) Write the name for the following:
a.) Na2SO3 ______
b.) NH4F ______
c.) CuCO3 ______
d.) FeCl3 ______
e.) CaO ______
12.) (5 points) Calculate the number of atoms in 40.5 g of aluminum.
13.) (5 points) A 2.25 g sample of magnesium nitrate contains ______moles of nitrate ions.
14.) (6 points) Calculate the percent composition of each atom in CaCO3.
15.) (10 points, 2 pt each) Balance the following equations:
a.) C4H10 + O2 à CO2 + H2O
b.) LiBF4 + H2O à H3BO3 + HF + LiF
c.) Fe(NO3)3 + NH3 + H2O à Fe(OH)3 + NH4NO3
d.) Ca(OH)2 + Cl2O7 à Ca(ClO4)2 + H2O
e.) ZrO2 + CCl4 à ZrCl4 + COCl2
16.) (6 points) How many moles of O2 are required to completely burn 1.10 moles of C6H6 according to the following equation?
2C6H6 + 15O2 à 12CO2 + 6H2O
17.) (6 points) What mass of phosphoric acid would actually react with 7.17 grams of LiOH? The equation for the reaction is:
3LiOH + H3PO4 à Li3 PO4 + 3H2O
18.) (6 points) Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide. How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II) carbonate?