Download CHEM 110 – Dr. McCorkle and more Study notes Chemistry in PDF only on Docsity!
DO NOT OPEN
UNTIL INSTRUCTED TO DO SO
CHEM 110 – Dr. McCorkle – Exam
While you wait, please complete the following information:
Name: _______________________________
Student ID: _______________________________
Turn off cellphones and stow them away. No headphones, mp3 players, hats,
sunglasses, food, drinks, restroom breaks, graphing calculators, programmable
calculators, or sharing calculators. Grade corrections for incorrectly marked or
incompletely erased answers will not be made.
- How many valence electrons do the halogens possess? A) 1 B) 2 C) 5 D) 6 E) 7
- Suppose a metal ejects electrons from its surface when struck by red light. What will happen if the surface is struck by blue light? A) No electrons would be ejected. B) Electrons would be ejected, and they would have the same kinetic energy as those ejected by red light. C) Electrons would be ejected, and they would have greater kinetic energy than those ejected by red light. D) Electrons would be ejected, and they would have lower kinetic energy than those ejected by red light.
- Identify the isoelectronic elements A) Cl−, F−, Br−, I−, At− B) N3−, S2−, Br−, Cs+, Sr2+ C) P3−, S2−, Cl−, K+, Ca2+ D) Zn2+, Co2+, Cu2+, Cr2+, Cd2+ E) Ne, Ar, Kr, Xe, He
- What period 3 element has the following ionization energies (all in kJ/mol)? IE 1 = 1012 IE 2 = 1900 IE 3 = 2910 IE 4 = 4960 IE 5 = 6270 IE 6 = 22,
A) Mg B) Si C) P D) S E) Cl
- Arrange the elements in order of increasing IE 1 : N, F, As A) N < As < F B) As < N < F C) F < N < As D) As < F < N E) F < As < N
- Arrange the elements in order of increasing metallic character: P, As, K A) P < As < K B) As < P < K C) K < P < As D) As < K < P E) K < As < P
Calculations – Write your initials in the upper-right corner of every page that contains work. For full credit show all work and write neatly; give answers with correct significant figures and units. For calculations, place a box around your final answer.
- For the following short answer questions, please circle, fill-in, or provide the correct answer. [2 points each]
a. Which transition has a longer wavelength? n = 7 → n = 5 n = 3 → n = 1
b. Which has the lowest energy? 6 s 5 d 4 f
c. A gas phase element gaining an electron is a typically endothermic process. True False
d. How many electrons in an atom could have n = 4, l = 2 , ml = +1? __________
e. The two most probable ions of titanium are __________ and __________.
- How many photons are contained in a flash of green light (525 nm) that contains 189 kJ of energy? [4 points]
dia- or para-
- Calculate the de Broglie wavelength in meters of a 45.9 g golf ball with a velocity of 52 m/s. [3 points]
- Explain the trends in atomic radius across a period (from left to right) and down a group (from top to bottom). [4 points]
- Consider the electronic transition within a hydrogen atom from n = 5 to n = 2.
a. Calculate the energy of the photon that is emitted in joules. [2 points]
b. Calculate the frequency in Hertz. [2 points]
c. Calculate the wavelength in meters. [2 points]
d. Does this emission occur within the visible region of the electromagnetic spectrum? [ points]
Formulas & Constants (you may or may not need)
1 inch = 2.54 cm (exact) 1 mile = 5280 ft ≈ 1.609 km 1 kg ≈ 2.205 lb
1 lb = 16 oz ≈ 453.6 g 1 gal = 4 qt = 8 pt ≈ 3.785 L 1 L = 1000 cm^3
K = C + 273.15 F = 1.8 x C + 32 C = (F – 32)/1.
1 cal = 4.184 J 1 Cal = 1000 cal q = m x C x ΔT
Avogadro’s # = 6.022x10^23 Molar volume = 22.4 L R = 0.08206 L∙atmmol∙K
P 1 V 1 T 1 =^
P 2 V 2 T 2 𝑢rms^ = √
3RT 𝑀 𝐾𝐸 =^
1 2 𝑚𝑣
(^2) = 3 2 𝑅𝑇
1 atm = 760 mmHg 1 mmHg = 1 torr PTotal = P 1 + P 2 + ...
PA = ΧA · PTotal PV = nRT ∆E = q + w
w = −P∆V q = C × ∆T q = m × s × ∆T
∆ H °rxn = Σ[n ∆ H f°(products)] – Σ[n ∆ H f°(reactants)] R = 8.314 J/mol · K
h = 6.626×10−^34 J · s c = 2.9979×10^8 m/s RH = 2.18×10−^18 J
1 Hz = s−^1 𝜆 = (^) 𝑚𝑣ℎ ∆𝑥 × 𝑚∆𝑣 ≥ (^) 4𝜋ℎ
Ephoton = hν = ℎ𝑐𝜆 Ephoton = R𝐻 [( (^) n^1 final^2 ) − ( (^) n^1 initial^2 )]
Scratch Page
(to be handed in)
