Download Exam 2A Fall 2004

Mixon CH131_F2004
Exam 2A
Table O’Information
1.
2.
3.
4.
5.
6.
Solubility:
All common compounds of Group I and ammonium ions are soluble.
All nitrates , acetates, and chlorates are soluble.
All binary compounds of the halogens Group VIIA (other than F) with metals are soluble,
except those of silver, mercury (I), and lead.
All sulfates are soluble, except those of barium, strontium, calcium, lead, silver, and mercury
(I). The latter three are slightly soluble.
Except for rule 1, carbonates, hydroxides, oxides, silicates, and phosphates are insoluble.
Sulfides are insoluble except for calcium, barium, strontium, magnesium, sodium,
potassium, and ammonium.
 1
1
E = -2.179 x 10-18J  2  2
n
nL
 H
E = h




h =6.626 x 10-34 Js
c = 
=
h
mv
c = 2.9979 x 108 m/sec
 1
1
1 
 R 2  2 
n
λ
n 2 
 1
R = 1.0968 x 10-7 m
NA = 6.022 x 1023
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Mixon CH131_F2004
Exam 2A
Name:_______________________________________________________ Date:_________________
1.)
A 10.00 mL sample of an aqueous solution of calcium hydroxide requires 23.30 mL of
0.02000M HNO3 (aq) for its neutralization, what is the molarity of Ca(OH)2 (aq)? (7 pts)
2HNO3 (aq) + Ca(OH)2(aq) → 2H2O(l) + Ca(NO3)2 (aq)
2.)
In the following reaction, indicate the oxidation numbers of each species, identify and
label the species being oxidized, the species being reduced, the oxidizing agent, and the
reducing agent and write the half-reactions: (8 pts)
3Mn(s) + 2Fe(NO3)3(aq) → 3Mn(NO3)2(aq) + 2Fe(s)
Mn:
→
Mn:
Fe:
→
Fe:
N:
→
N:
O:
→
O:
Oxidation half-reaction:
Reduction half-reaction:
Species oxidized:______________
Species reduced:_____________
Oxidizing agent:_______________
Reducing Agent:________________
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Mixon CH131_F2004
3.)
Exam 2A
Complete the following chemical reactions and balance each. Predict whether a
precipitation reaction will occur in each of the following cases. IF (and only if) a
precipitate forms, write the ionic and net-ionic equations – show phases!!: (12 pts)
a.) (NH4)2SO4 + Cu(NO3)2 →
ionic:
net-ionic:
b.) K2CO3 + ZnCl2 →
ionic:
net-ionic:
c.) Pb3(PO4)4 + HCl →
ionic:
net-ionic:
4.)
Write/list all of the components in the visible spectrum in order from INCREASING
(largest) to DECREASING (smallest) wavelength. Put the species with the largest
wavelength on the left and the species with the smallest wavelength on the right (4 pts)
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Mixon CH131_F2004
5.)
Exam 2A
Given the following equation, calculate the number of moles of NH3 (g) that will be
produced from 12.25 grams of N2 (g) and 6.25 grams of H2 (g). (8 pts)
N2 (g) + 3H2 (g) → 2NH3 (g)
Which reactant is the limiting reactant:___________________ (2 pts)
6.)
Name the following: (8 pts)
a.) Fe(NO3)3
b.) Cu3(PO4)2
c.) HCl
d.) Zn(ClO3)2
7.)
Given 2.56 grams of Ba3(PO3)2 calculate the number of PO3-3 ions are present in the
compound (MM Ba3(PO3)2 = 569.87 grams/mole) (4 pts)
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Mixon CH131_F2004
Exam 2A
8.)
Calculate the wavelength for a transition that occurs when an electron falls from the n=5
to the n=3 level (BONUS 2 pts: who is this transition named after and what region of the
EM spectrum does it correspond to?) (5 pts)
9.)
Calculate and indicate which species is more energetic: green light (wavelength = 525
nm) or yellow light (595 nm) (7 pts)
10.) Calculate the energy associated with an electron falling from the n=6 to the n=1 level (5
pts)
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