CHM 100             Test I            Fall, 1998

c = 3.0 x 108 m/s                 N = 6.02 x 1023                       1 amu = 1.66x10-24 g
1.We concluded in class that perception is

a.  a chemical process which should not be discussed in psychological terms like “illusion,” etc.

b.  a psychological process, to which molecular understanding has no relevance.

c.  both psychological and chemical, depending on what models were used to understand it.

d.  outside the realm of physical science.

e.  none of these.
 
 
 
 

2.  Methane, CH4, is a mixture of carbon and hydrogen.    a.    True    b.    False

3.  A segment of a burette is shown at right.  What random error would be assigned to this device according to our rules?

a.    1 mL     b.    0.5 mL    c.    0.05 mL     d.  0.6 mL    e.  0.1 mL
 

4.  The meniscus over a volume of liquid is shown.  How should the volume measurement be recored, according to our rule?

a.  2 mL        b.  3 mL        c.  2.0 mL        d.  2.6 mL e. 2.60 mL
 

 
 
 

5.  What is the best way to determine the absolute error (accuracy) of the burette?
 

a.  define it as ½ the smallest scale division.

b.  define it as the standard deviation of several measurements.

c.  define it as  the percent random error.

d.  compare several measurements made with the burette.

e.  a measurement with another device is needed to assess the accuracy of the burette.
 

 

6.  A chemical process is necessary to separate gasoline into its components.  a.  True  b.  False
 

 
 

7.  Please convert 128 oz to kg, where 16.0 oz  = 1.00 lb and 1.00 lb = 454 g.

a.  2.71        b.  3.63        c.  4.28        d.  6.92        e.  none of these
 

 
 
 

8.  What is the density of a substance in g/cm3 if 10.0 in3 weights 1.87 lb , given that 2.54 cm = 1.00 inch and 1.00 lb = 454 g?
 

 
 

a.  5.18         b.  6.46        c.  7.22        d.  8.64        e. 9.38
 

9.Clean air is

a.a homogeneous, pure substance

b.a heterogeneous, pure substance

c.homogeneous and impure

d.heterogeneous and impure

e.a compound of O2, N2, and several other minor gases.

10.The sum and product of 333.4 cm and 0.0022 cm have, respectively, how many significant figures?

ProductSum

a.44

b.22

c.42

d.24

e.some other combination.

11.Every element has a characteristic mass number.a. Trueb.False

12.How many protons, neutrons, and electrons are there in the 5928Ni2+ ion?

#protons#neutrons#electrons

a.592857

b.285930

c.285926

d.283130

e.283126

13.The nucleus contains 99.9% of the mass of an atom in less than a billionth (10-9) of its volume.

a.Trueb.False

14.The emission of an alpha particle from21884Po yields

a. 21484Po    b. 21682Pb     c.21482Pb     d.21885At    e. 21884Po

15.What is the missing product, X, in the nuclear equation below, where n is a neutron?

n + 147N®146C + X

a.beta    b.alpha    c.gamma    d.positron    e.proton

16.Which isotope is most likely to decay by positron emission?

a.3417Cl    b.3517Cl    c. 3617Cl    d. 3717Cl    e.3817Cl

17.If a sample is marked 0.20 microCuries, what is its disintegration rate in disintigrations/minute?[1 Curie = 3.7 x 1010 d/second].

a. 7.4 x 106    b.7.4 x 103    c.4.4 x108    d. 4.4 x 105    e.3.7 x 103

18.If a gamma particle, a beta particle, an alpha particle, a proton, and a positron, all having the same velocity, were directed through a magnetic field, which would follow the straightest path?

a.gamma    b.beta    c.alpha    d.positron    e.proton

19.Which is probably the least stable of the following nuclides?

a.126C    b.5626Fe    c.3115P    d.7934Se    e.6429Cu

20.How much energy (in J) is released by the “big bang” reaction that is postulated as the beginning of the universe?In the reaction, a neutron decays to a proton and a beta particle, with the masses listed below.

neutron®proton + electron

mass, amu1.008671.007830.00055

a.4.3 x 10-14 J    b.5.8 x 10-15 J    c.7.4 x 10-16 J    d.8.5 x 10-17 J    e.3.2 x 10-17 J

21.An element from another galaxy has three isotopes as follows:

IsotopeMass% Abundance

3316Á    33.11    25%

3416Á    34.00    55%

3516Á    34.98    20%

What is the atomic weight of the element?

a. 34.27    b.34.03    c.33.97    d.33.66    e.33.42

22.A chemical property of phosphorus which was demonstrated in the lecture experiment was

a.it reacts with oxygen to give a product which dissolved in water to give a basic solution.

b.phosphorus reacted with CS2 to give PS4.

c.the phosphorus reacted with water with fizzing and popping.

d.phosphorus burns in air without being ignited.

e.phosphorus has typical properties of a metal.

23.The law of periodicity states that properties of elements vary periodically

a.because of periodic changes in nuclear structure

b.down groups of the periodic table

c.so that metal oxides vary from acidic to basic.

d.so that if a Group I oxide is exemplified by formulas like Na2O, then we would expect Group II oxides to be exemplified by formulas like CaO.

e.so that metals are at the top of groups and nonmetals at the bottom.

24.How many moles of atoms are there in two moles of H2O?

a.2    b.3    c.6    d.2 x 6.02 x 1023    e.6 x 6.02 x 1023

25.In the chemical equationCH4 + 2 O2®2 H2O + CO2, how many moles ofoxygen molecules (O2) are consumed when 4 moles of CO2 are produced?

a.½    b.¼    c.2    d.4    e.8

26.What amount of sulfur atoms is represented by 243 g of sulfur, S?

a.243 mLb.7.6 molc.0.243 kgd.0.13 mole.7.8 x 103 mol