Chem 101
Exam 1
Name:_____________________________________
Please put each of your answers on the front cover to make it easier for grading. I will also check in the test booklet for problems that require calculations. If the answer is wrong, partial credit will be given whenever possible. All questions are worth the same amount. You must have calculations present within the test to get credit for an answer even if the answer is correct.
1
a. substance
Group of identical molecules
Boiling point gas at room temperature, etc.
2
2700 kg/m3
2.70x103 kg/m3
3
3 A material that does not break up into ions.
sugar
a. the light bulb would not light at all
4
Potassium sulfate
+1
Sulfate ion SO42-
5 2NaHCO3 → Na2CO3 + H2O + CO2
78.3g
89.8%
6
2NaOH + H2SO4 → Na2SO4 (aq) + 2H2O
0.0522M
5.228 x 10-3 moles
7
15
15
16
8
3.37 x 1026 atoms
28.0g
46.7%
Constants 23 n = 6.02 x 10 /mol g = 9.807 m/s
2
Conversions T (K) = t (0ºC) + 273.15 1N = 1kg m/s
2 2 2
Equations d=m/V P=g xd xh dHgx hHg = dl x hl PV = nRT P1V1 = P2V2 V1 / T1 = V2 / T2 V1 / n1 = V2 / n2 Ptotal = P1 + P2 + P3 + P1/Ptotal = n1/ntotal = x1 Pa = Xa x Pa° P1 = x1 Ptotal (P + an /V )(V-nb) = nRT P1V1 = P2V2 n1T1 n2T2
2 2 2 . …
Equations . . 2 . . RT = 2/3 N A mu = 2/3 N A Ek urms = ∆H = qp w = -P∆V KE = 1/2 mv ∆U = q + w ∆Hrxn = ∆H1 + ∆H2 + ∆H3 +... q = mass x S.H. x ∆T C = q/∆T S.H. = q/m∆T ∆Tb = iKbm molar heat capacity = S.H. x molar mass BO = ½ (# BE - # ABE) ∆Tf = -iKfm E = hν Elevel = B (1/ni – 1/nf ) Ephoton = hc/λ
2 2 2
(3RT)/M
R = 0.0821 L atm / mol K R = 8.3145 J/(mol K) me / e = –5.686 X 10 e = -1.602 X 10
-19 -12 .
P = N/m = kg / ms Joule = kg/m s
2 2
kg\C
1 atm
= 760 mmHg = 760 torr = 1.01325 bar = 29.921 in. Hg
C kg\ electron
me = 9.109 X 10 c =3.0 x 10 m/s h = 6.626 X 10
8
-31
-34 -18
Js J
= 101.325 kPa
B = 2.179 X 10
π = iMRT
xi = ni / ntotal...