CH1410 Practice Exam #2 (Katz)
Section 1 - Multiple Choice - Write the letter of the BEST CHOICE in the space provided.
_____ 1. How are wavelength and frequency of light related?
A) Wavelength is one-half of the frequency.
B) Wavelength is double the frequency.
C) Wavelength increases as frequency increases.
D) Wavelength increases as the frequency decreases..
_____ 2. Which form of electromagnetic radiation has the longest wavelength?
A) Radio Waves!
!
B) Microwaves! !
C) X-rays!
!
D) Gamma Rays
_____ 3. Which statement below does NOT follow the Bohr Model?
A) When energy is absorbed by atoms, the electrons are promoted to higher-energy orbits.
B) When an atom emits light, electrons fall from a higher orbit into a lower orbit.
C) The energy emitted from a relaxing electron can have any wavelength.
D) Electrons exist in specific, quantized orbits.
_____ 4. The energy sublevel for the highest energy electrons added to the elements U,
the correct order,
A) s, p, d, f! !
C) p, d,f, s.! !
!
!
!
!
Sr, Cl, and Cu are, in
B) f,s,p,d.
D) f,p,d,s.
_____ 5. Which subshell letter corresponds to a spherical orbital?
A) s!
!
B) p!
!
C) d!
!
D) f
_____ 6. What is the electron configuration for Kr?
!
!
A) 1s22s22p63s23p43d104s24p6! !
C) 1s22s22p63s23p64s23d104p6! !
!
!
!
!
B) 1s22s22p63s23p64s23d24p6
D) 1s22s22p63s23p24s23d104p6
_____ 7. Consider the electron configuration of the ion to determine which ion shown below has an incorrect
ionic charge?
A) Al3+
B) Se2+
C) Rb+
D) Ba2+
_____ 8. Which one of the following species has the electron configuration of 1s22s22p6?
!
1. Na+
A) 1 and 2 only!
C) 2 and 3 only!
3. F-
2. O2!
!
!
!
!
!
B) 1 and 3 only
D) 1, 2, and 3
_____ 9. ) Which of the following atoms is the largest?
A) Na!
!
B) K!
!
C) Rb! !
D) Cs
_____10. Which of the following atoms has the greatest metallic character?
A) Cs!
!
B) Be!
!
C) Cu! !
D) Ti
_____11. How many carbon atoms are in the formula Al2(CO3)3?
A) 9!
!
B) 6!
!
C) 3!
!
D) 1
_____12. How many of each type of atom are there in the formula (NH4)2HPO4?
A) N = 2, H = 9, P = 1, O = 4
B) N = 1, H = 5, P = 1, O = 4
C) N = 2, H = 5, P = 1, O = 4
D) N = 2, H = 8, P = 1, O = 4
_____13. Which among the following elements does NOT exist as a diatomic molecule in nature?
A) hydrogen!
!
B) nitrogen!
!
C) fluorine!
!
_____14 ) Which of the following is a molecular compound?
A) barium sulfide! !
C) potassium hydroxide!
!
!
!
!
!
!
B) calcium acetate
D) nitrogen monoxide
!
!
!
!
B) cobalt sulfide
D) cobaltous sulfur
!
!
B) calcium nitrate
D) calcium nitrite
_____15. What is the name of CoS?
A) cobalt(II) sulfide! !
C) cobalt monosulfide!
!
!
_____16. ) What is the name of Ca(NO3)2?
A) calcium dinitrite! !
C) calcium nitride! !
!
!
!
!
_____17. What is the correct formula for potassium dichromate?
A) K(CrO4)2
B) KCr2O7
C) K2CrO4
D) K2Cr2O7
_____18. The charge of a vanadium ion in the compound V2O5 is:
A) 5+
B) 2+
C) 10+
D) 10-
D) neon
_____19. What is the name of the molecular compound SO3?
A) sulfur oxide
B) sulfur(IV) oxide
C) sulfur trioxide
D) sulfur tetraoxide
_____20. What is the proper name for HBr (aq)?
A) hydrobromous acid
B) hydrousbromic acid
C) hydrobromic acid
D) bromous acidD) an isotope.
_____21. What is the formula mass for potassium nitrate?
A) 92.99 amu
B) 117.11 amu
C) 85.11 amu
D) 101.10 amu
_____22. A compound has a formula mass of 61.98 amu and is comprised of atoms of sodium and oxygen in a
definite ratio. The name of the compound described here is
A) sodium monoxide.
B) disodium oxide.
C) sodium oxide.
D) sodium dioxide.
_____23. A chromium oxide compound contains 104.0 grams of chromium and 48.0 grams of oxygen. What is
the most likely empirical formula of this compound?
A) CrO
B) CrO2
C) CrO3
D) Cr2O3
_____24. What is the molecular formula of a compound given the molar mass of the compound is 30.04 gram
and the empirical formula is NH?
A) NH
B) N2H2
C) N2H6
D) N4H4
_____25. If you have 1.81 x 1024 atoms of copper, how many moles of copper do you have?
A) 0.330
B) 3.00
C) 0.750
D) 2.00
_____26. How many atoms of lithium are in 11.8 g of Li?
A) 1.35 x 1024
B) 1.70 x 1024
C) 1.02 x 1024
D) 2.22 x 1024
_____ 27. How many moles of oxygen are in 3.70 moles of NaClO4?
A) 3.70
B) 0.270
C) 21.5
D) 14.8
_____28. What is the mass percent of Mg in magnesium chloride (MgCl2)?
A) 12.3
B) 40.7
C) 25.6
D) 68.3
_____29. When the equation, ___O2 + ___C5H12 → ___CO2 + ___H2O is balanced, the coefficient:
of O2 is:
A) 3
B) 4
C) 5
D) 8
_____ 30. What are the coefficients for the following reaction when it is properly balanced?
___Na3PO4 + ___Ba(NO3)2 → ___NaNO3 + ___Ba3(PO4)2
A) 2, 1, 1, 3
B) 2, 3, 1, 6
C) 2, 3, 6, 1
D) 6, 1, 3, 2
_____31. What are the coefficients for the following reaction when it is properly balanced?
___nitrogen monoxide + ___carbon monoxide → ___nitrogen +___carbon dioxide
A) 2, 1, 1, 2
B) 2, 2, 1, 2
C) 2, 2, 2, 1
D) 1, 1, 2, 2
2 NO + 2 CO -----> N2 + 2 CO2
_____32. Sodium metal reacts with water to form aqueous sodium hydroxide and hydrogen gas. Which equation
below best describes the balanced equation for this reaction?
A) Na + H2O → NaOH (aq) + H (g)
B) S + H2O → SOH (aq) + H (g)
C) Na + H2O → NaOH (aq) + H2 (g)
D) 2Na + 2H2O → 2NaOH (aq) + H2 (g)
Section 2 - Answer the following computational questions using the information provided. You
must show a plan for your calculations, along with the conversion factors involved for full credit .
Write your answer in the box provided.
1. How many atoms of potassium are contained in 3.00 mol of K3PO4?
(Avogadro’s number = 6.022 x 1023)
Plan and Calculations:
3.00 mol K3PO4 X 3 mol K atoms X 6.022 x 1023 K atoms = 5.42 x 1024
1 mol K3PO4
1 mol K atoms
2. How many moles of calcium phosphate are in 50.00 g of Ca3(PO4)2?
(atomic weights: Ca, 40.08; P, 30.97; O, 16.00)
Molar Mass Calculation:
3 x 40.08 =
2 x 30.97 =
8 x 16.00 =
120.24
61.94
128.00
310.18
g/mol
Plan and Calculations:
50.00 Ca3(PO4)2
1 mol Ca3(PO4)2
X 310.18 g Ca (PO )
3
4 2
= 0.1612 mol Ca3(PO4)2
K atoms
3. How many moles of carbon are contained in 100.00 g of Pb(CO3)2?
(atomic weights: Pb, 207.2; C, 12.01; O, 16.00)
Molar Mass Calculation:
1 x 207.2 =
2 x 12.10 =
6 x 16.00 =
207.2
24.02
96.00
327.22
g/mol
Plan and Calculations:
100.00 g Pb(CO3)2
X
1 mol Pb(CO3)2
X
327.22 g Pb(CO3)2
__2 mol C___
= 0.6112 mol C
1 mol Pb(CO3)2
4. How many grams of sodium are contained in 15.00 g of NaHCO3 (molar mass = 84.01)?
!
!
!
!
Plan and Calculations:
15.00 g NaHCO3
X
1 mol NaHCO3 X _1 mol Na___ X
84.01 g NaHCO3
1 mol NaHCO3
22.99 g Na = 4.105 g Na
1 mol Na