Electron Configuration
Mass Percent
Empirical Formula
Law of Conservation of Mass
Mixed
100
What is the electron configuration for Al?
1s2 2s2 2p6 3s2 3p1.
100
What are the mass % of carbon and oxygen in carbon dioxide, CO2?
mass % C = 27.29 % mass % O = 72.71 %
100
What is the empirical formula of a compound containing 60.0% sulfur and 40.0% oxygen by mass?
SO3
100
What is the sum of the coefficients when the following equation is balanced with the most reduced whole numbers? Al(OH)3 + H2SO4 → Al2(SO4)3 + H2O
2Al(OH)3 + 3H2SO4 --> Al2(SO4)3 + 6H2O 12
100
Which of the following is the most abundant isotope of chlorine? Chlorine-35 Chlorine-35.45 Chlorine-36 Chlorine-37
Chlorine-35
200
Which of the following elements has the largest number of electrons for which the principal quantum number, n, is 3? Si, Ar, Cl, or Zn?
Zn.
200
Calculate the percent by weight of sodium (Na) and chlorine (Cl) in sodium chloride (NaCl)
Na: 39.34% Cl: 60.66%
200
A compound is found to contain 23.3% magnesium, 30.7% sulfur and 46.0% oxygen. What is the empirical formula of this compound?
MgSO3
200
Consider the following balanced chemical reaction: SnO2(s) + 2 H2(g) → Sn(s) + 2 H2O(g). If 1 L of hydrogen gas is reacted with excess tin (IV) oxide, how many liters of water vapor will be produced?
1L
200
What is the average atomic mass of a sample of natural occuring X if it is comprised of the following isotopes: 47% 51X, 17% 52X, 36% 56X?
52.97.
300
An element with an electron configuration of 1s2 2s2 2p6 3s1 will have properties most similar to which elements?
Cs, H, Li, K, Rb, Fr.
300
What is the mass percent of sodium hydroxide in a solution that is made by dissolving 8.00g NaOH in 50.0g H2O?
Mass percent = 13.8% NaOH solution
300
A sample of an oxide of nitrogen is found to contain 30.4% nitrogen. What is its empirical formula?
NO2
300
What is the concentration of an NaOH solution if it takes 12.50 mL of a 0.100 M HCl solution to titrate 25.00 mL of the NaOH solution?
0.0500 M
300
When 16.0 g of methane react with chlorine, 40.5 g of methyl chloride and 36.5 g of hydrogen chloride form. How much chlorine was used?
Cl = 61.0 g.
400
What element could have an electron configuration of 1s2 2s2 2p6 3s2 3p4 4s1
Potassium.
400
Calculate the percent by weight of each element present in sodium sulfate (Na2SO4).
Na: 32.37% S: 22.57% O: 45.06%
400
What is the empirical formula of a compound comprised of 1.8% hydrogen, 56.1% sulfur and 42.1% oxygen?
H2S2O3
400
A sample of 25.0 mL of 0.120 M Ba(OH)2 is titrated with 0.150 M HBr. What volume of hydrobromic acid is needed to completely neutralize the barium hydroxide?
40.0 mL
400
The average atomic mass of bromine is 79.90 amu. Bromine consists of two isotopes: Bromine-79 and Bromine-81. Which of the following is the best approximate relative abundance of these two isotopes? 100% Bromine-79 and 0% Bromine-81 90% Bromine-79 and 10% Bromine-81 50% Bromine-79 and 50% Bromine-81 25% Bromine-79 and 75% Bromine-81
50% Bromine-79 and 50% Bromine-81.
500
What is the electron configuration for Po?
[Xe] 6s2 4f14 5d10 6p4.
500
What is the mass percent of potassium in K3Fe(CN)6?
K: 8.70%
500
A borane is a compound containing only boron and hydrogen. If a borane is found to contain 88.45% boron, what is its empirical formula?
B5H7
500
Through the process of photosynthesis, 5.00 g of glucose (C6H12O6) is created by a corn plant. This corn is eaten by a herd of deer who migrate to a different habitat and eventually die. How much of the carbon in the 5.00 g of glucose produced by the original corn plant is still present on Earth after the deer die?
All 5.00 g of carbon remain on earth
500
A sample of blue copper (II) sulfate is analyzed using a spectrophotometer (or colorimeter). The solution when analyzed by 4 different wavelengths obtains the following absorbance data: 425 nm = 0.12, 480 = 0.25, 510 nm = 0.98, 610 nm = 0.11. What is the optimum wavelength(s) to be used for analysis?
510 nm.
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