Name Practice CWID Section ___________
Sections (Lab) 27561 (M AM), 27562, (M PM), 27563 (T PM), 27564 (W AM), 27565 (Th PM)
27567 (F, AM), 27571 (Th AM)
Chemistry 1515 F24
Hour Exam #1 (Blum)
Instructions: You may use a calculator. Only this top page (for multiple choice) and the
"show work" problems will be graded. Mark your letters clearly (UPPER CASE PLEASE).
If we can't easily determine your intention, it will be marked as incorrect. Multiple choice 4 pts
ea., show work problems 7 pts ea.
For multiple choice questions, answers elsewhere on these problems will not be graded.
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Answer
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Answer
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Answer
1
7
13
2
8
14
3
9
15
4
10
16
5
11
17
6
12
18
Total
For worked problems – Show answer and your work on attached pages (not here). Make
sure your answers are clearly marked with a box and remember to include units.
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Score
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Score
Top Total
/72
19
21
Bottom Total
/28
20
22
Grand Total
/100
0 pts. The given name of the person called Pistol Pete was _____________________
Possibly useful constants: R=8.314 J/(k mol) = 0.08206 L atm/(K mol), NA = 6.022x10-23
Some constants for water. ρ (water) = 1.00 g/mL, Cp(solid) = 37.7 J/(mol⋅K), Cp(liquid) =75.4
J/(mol⋅K), ∆Hfusion = 6.01 kJ/mol, ∆Hvaporization = 40.7 kJ/mol, ∆Hsublimation = 51.1 kJ/mol (You may
assume that these are constant with temperature, hence CP.)
Equations: q = n Cp ∆T or q = m Cp ∆T; q = n ∆Hwhatever or q = m ∆Hwhatever
lnP!"#$% %=
'
−∆'!"#$%
(
)
%× )
*%+ %const.
You need to derive equation for P1, P2, T1, T2
Amountgas = kHL Pgas; % mass = mass solute/total massx100%; XA = molA/(molA+molB);
m = moles solute/kg solvent; PA = XA•P°; Ptotal = PA + PB; (molA/molB)vap = PA/PB;
(XB)vap = PB/Ptotal; ∆Tf = -Kfm, ∆Tb = Kbm; πV = nRT;
for electrolytes modify with i=mol of species in soln./mol solute dissolved
Note: Be careful to distinguish between molality (m) and molarity (M).
Your answers here
