Chemistry 161. Test One. February 13, 2015. Name ______________KEY___________________________________
This test is pledged non-disclosure until it is returned.
Part One. Thirty points, 2 points each.
C 1) Liquid nitrogen boils at 77.0 K. What is the boiling point in o F? a- -141.0 o F b- 171.0 o F c- -321.0 o F d- -196 o F
77.0 K -273.15 = -196.2 o C
(9/5)(-196.15) + 32 = -321.1 o C
B 2) Which of the following best describes a solid?
1. definite volume
2. definite shape
3. fluid a- 1, 2, and 3 b- 1 and 2 only c- 1 only d- 2 only
A 3) Which of the following is an example of a chemical change? a- hydrogen burning (to become water and changes chemical identity) b- sugar dissolving c- dry ice subliming d- water boiling
D 4) What is the ratio of atoms of hydrogen to atoms of sulfur in ammonium sulfate, (NH
4
)
2
SO
4
? a- 1 : 4 b- 2 : 7 c- 2 : 1 d- 8 : 1
D 5) The symbol for sodium is a- So (no element) b- S (sulfur) c- Sm (samarium) d- Na
C 6) A mL is a cubic centimeter. What is the volume of a cubic meter? a- 10 L 1 m 3 * (100 cm / m) 3 = 1 x 106 cm 3 b- 100 L c- 1000 L
1 x 10 6 cm 3 * 1 ml / 1 cm 3 = 1 x 10 6 mL
1 x 10 6 mL * 1 L / 1000 mL = 1 x 10 3 L d- 10,000 L
A
7) Which of the following is not a postulate of Dalton’s atomic theory? a- Elements combine by forming ionic or covalent bonds b- An element is composed of atoms which are indestructible c- All atoms of a given element are the same d- Elements cannot be changed into other elements

C 8) For 0.002451 x 10 6 would be correctly written as a- 2.451 x 10 6 The mantissa of a properly written number is between 1 and 10.
b- 0.2451 x 10 4 c- 2.451 x 10 3 d- the number is correctly written
D 9) The mass of an electron was established by a- the work of Thomson b- the work of Milliken c- the work of Becquerel mass / charge ratio of electron charge of electron radioactivity d- the combined work of Milliken and Thomson
B 10) Which of the following compounds will be ionic? a- CO
2 b- BaF c- AsBr
3 d- Al
2
O
3
A 11) The species
25
53 Mn 2+ c- d- e- f- g- h- a- has 25 protons, 28 neutrons, and 23 electrons b- has 28 protons, 25 neutrons, and 26 electrons c- has 25 protons, 28 neutrons, and 27 electrons d- has 12 protons, 31 neutrons, and 10 electrons
D 12) The symbol for copper is a- C – is carbon b- Cr – is chromium c- Co – is cobalt d- Cu
B 13) Avogadro’s number is a- 6.022 x 10 -23 b- 6.022 x 10 23 c- 6.626 x 10 -34 d- 1.675 x 10 -27
Part Two.
1) (4 points) What seven elements commonly exist as diatomic molecules?
Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine
2) (16 points) Nomenclature.
Name a- b-
Hydrogen bromide
Calcium iodide
Ammonia
Vanadium(V) oxide
Potassium hydroxide
Nickel(II) cyanide
Strontium sulfide
Iron(III) fluoride
Ionic or Molecular Formula
HBr
CaI
NH
V
2
O
FeF
3
SrS
2
5
3
KOH
Ni(CN)
2

3) (12 points) Conversions. Show the problem set up and the answer! a- The density of titanium is 4.51 g/cm 3 . What is the volume in m 3 of 1.000 kg of titanium?
1.000 kg * 1000 g/kg = 1000 g Ti
1000 g Ti / 4.51 g/cm3 = 2.22 x 10 2 cm
2.22 x 10 2 cm 3 * (1 m / 100 cm) 3
3
= 2.22 x 10 -4 m 3 b- A compound is 47.8% by weight of silicon. How many grams of the compound are needed to have 675 g of silicon?
Unknown mass * .478 ratio by weight of Si = 675 g Si
Unknown mass = 675 g Si / 0.478 ratio by weight = 1.41 x 10 3 g
4) (21 points)Definitions. Remember that you should not use the term in the definition.
Hypothesis – a
Physical Property -
Accuracy -
Matter -
Chemical -
Isotope – species that have the same number of protons but differ in the number of neutrons
AMU – atomic mass unit equal to 1/12 the mass of a carbon-12 atom.