Download Exam 1B Fall 2004

A. Mixon
Exam 1B: CH131 Fall 2004
Name:_________________________________ Date:___________________ Lecture:
9 a.m.
10 a.m.
Equations and Conversions
oF
= 9/5oC + 32
oC
= 5/9[oF-32]
1 cm3 = 1 ml
12 in = 1 foot
1 kg = 2.205 lb
5,280 ft = 1 mi
1 in = 2.54 cm
1 amu = 1.6606 x 10-24 g
NA = 6.022 x 1023
SHOW ALL WORK!!! NO WORK, NO CREDIT!! SHOW ALL WORK!!! NO WORK, NO CREDIT!!
SHOW ALL WORK!!! NO WORK, NO CREDIT!! SHOW ALL WORK!!! NO WORK, NO CREDIT!!
SHOW ALL WORK!!! NO WORK, NO CREDIT!! SHOW ALL WORK!!! NO WORK, NO CREDIT!!
1.) Identify the following as physical or chemical changes (5 pts):
a. Ice melting
b. Consumption (eating) of food
c. Breaking rocks into smaller pieces
d. Pennies tarnishing
e. Oil floating on water
2.) Convert 68.5oC to oF and K (5 pts)
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A. Mixon
Exam 1B: CH131 Fall 2004
4.) Convert 23
miles
meters
into
(4 pts)
2
hr 2
millisecon ds
5.)
How many significant figures in 1507.4120 (1 pts)
6.)
Element X has 35 protons and exists as an ion with 36 electrons. Identify the element and write
its symbol including the mass number, atomic number and charge (4 pts)
7.)
Calculate the molar mass of Ba(NO3)2 (5 pts)
8.) Calculate the number of protons, neutrons, and electrons in (9 pts):
Species
# of Protons
# of Neutrons
23Na+1
31P-3
7Li
2
# of Electrons
A. Mixon
Exam 1B: CH131 Fall 2004
9.) Give the name of the element from the following symbols (5 pts):
a. Na
b. K
c. S
d. F
e. Mg
10.) Write molecular formulas for the following compounds (8 pts):
a. Ammonium nitrite
b. Diboron heptanitride
c. Carbon tetrachloride
d. Aluminum sulfate
11.) Name the following compounds (8 pts):
a. CO
b. MgCO3
c. Ca(OH)2
d. Li2S
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A. Mixon
Exam 1B: CH131 Fall 2004
12.) Given the following isotopic data, calculate the average atomic mass for magnesium. (8 pts)
Isotope
24Mg
25Mg
26Mg
Mass (amu)
23.9850
24.9858
25.9826
13.) Calculate the mass, in grams, of 1.8066 x 1024 Sn atoms: (4 pts)
14.)
How many Ba ions are there in 5.75 g of Ba(NO3)2? (4 pts)
4
Abundance (%)
78.99
10.00
11.01
A. Mixon
Exam 1B: CH131 Fall 2004
Bonus: (2pts) Explain the major contribution to the changing structure of the atom by either Thomson or
Rutherford. Draw a picture of their “theory” for the structure of the atom.
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