Download Chapter 1, 2, 3, 4 Percent Composition, Ions, Stoichiometry

Chapter 1, 2, 3, 4
Percent Composition, Ions, Stoichiometry
Chemical Reactions
1.
Forms monatomic ions with a 2- charge in solutions.
(A) F (B) S (C) Mg (D) Ar (E) Mn
2.
Forms a compound having the formula KXO4
(A) F (B) S (C) Mg (D) Ar (E) Mn
3.
A 27.0-gram sample of an unknown hydrocarbon was burned in excess oxygen to
form 88.0 grams of carbon dioxide and 27.0 grams of water. What is the possible
molecular formula of the hydrocarbon?
(A) CH4 (B) C2H2 (C) C4H3 (D) C4H6 (E) C4H10
4.
What mass of Au is produced when 0.0500 mol of Au2S3 is reduced completely
with excess H2?
(A) 9.85g (B) 19.7g (C) 24.5g (D) 39.4g (E) 48.9g
5.
When hafnium metal is heated in an atmosphere of chlorine gas, the product of
the reaction is found to contain 62.2 percent Hf by mass and 37.4 percent Cl by
mass. What is the empirical formula for this compound?
(A) HfCl (B) HfCl2 (C) HfCl3 (D) HfCl4 (E) Hf2Cl3
6.
After completing an experiment to determine gravimetrically the percentage of
water in a hydrate, a student reported a value of 38 percent. The correct value for
the percentage of water in the hydrate is 51 percent. Which of the following is the
most likely explanation for this difference?
(A) Strong initial heating caused some of the hydrate sample to splatter out
(B) The dehydrated sample absorbed moisture after heating
(C) The amount of the hydrate sample used was too small
(D) The crucible was not heated to constant mass before use
(E) Excess heating caused the dehydrated sample to decompose
Chapter 1, 2, 3, 4
Percent Composition, Ions, Stoichiometry
Chemical Reactions
7.
In which of the following compounds is the mass ratio of chromium to oxygen
closest to 1.62 to 1.00?
(A) CrO3 (B) CrO2 (C) CrO (D) Cr2O (E) Cr2O3
8.
How many grams of calcium nitrate, Ca(NO3)2 contains 24 grams of oxygen
atoms?
(A) 164g (B) 96g (C) 63g (D) 50g (E) 41g
9.
The mass of element Q found in 1.00 mole of each of four different compounds is
38.0 grams, 57.0 grams, 76.0 grams, and 114 grams, respectively. A possible
atomic weight of Q is:
(A) 12.7 (B) 19.0 (C) 27.5 (D) 38.0 (E) 57.0
10.
The simplest formula for an oxide of nitrogen that is 36.8 percent nitrogen by
weight is:
(A) N2O (B) NO (C) NO2 (D) N2O3 (E) N2O5
11.
When a hydrate of Na2CO3 is heated until all the water is removed, it loses 54.3
percent of its mass. The formula of the hydrate is:
(A) Na2CO3 . 10H2O
(B) Na2CO3 . 7H2O
(C) Na2CO3 . 5H2O
(D) Na2CO3 . 3H2O
(E) Na2CO3 . H2O
12. A compound contains 1.10 mole of K, 0.55 mole of Te, and 1.65 mole of O. What is
the simplest formula of this compound?
(A) KTeO
(B) KTe2O
(C) K2TeO3 (D) K2TeO6 (E) K4TeO6
13.
The reaction of silver metal and dilute nitric acid proceeds according to the
equation above. If 0.10 mole of powdered silver is added to 10 ml of 6.0-molar
nitric acid, the number of moles of NO gas that can be formed is:
3Ag(s) + 4HNO3  3AgNO3 + NO(g) + 2H2O
(A) 0.015 mole (B) 0.020 mole (C) 0.030 mole (D) 0.045 mole (E) 0.090 mole
14.
What number of moles of O2 is needed to produce 14.2 grams of P4O10 from P?
Molecular weight P4O10=284)
(A) 0.0500 mole (B) 0.0625 mole (C) 0.125 mole (D) 0.250 mole (E) 0.500 mole
15.
When the equation above is balanced and all coefficients are reduced to their
lowest whole-number terms, the coefficient for O2(g) is:
…C10H12O4S(s) + …O2(g)  …CO2(g) + …SO2(g) + …H2O(g)
(A) 6 (B) 7 (C) 12 (D) 14 (E) 28
Chapter 1, 2, 3, 4
Percent Composition, Ions, Stoichiometry
Chemical Reactions
16.
According to the balanced equation below, how many moles of HI would be
necessary to produce 2.5 mol of I2, starting with 4.0 mol of KMnO4 and 3.0 mol
of H2SO4?
10 HI + 2 KMnO4 + 3 H2SO4  5 I2 + 2 MnO4 + K2SO4 + 8 H2O
(A) 20 (B) 10 (C) 8.0 (D) 5.0 (E) 2.5
17.
It is suggested that SO2 (molar mass 64 grams), which contributes to acid rain,
could be removed from a stream of waste gases by bubbling the gases through
0.25-molar KOH, thereby producing K2SO3. What is the maximum mass of SO2
that could be removed by 1,000. liters of the KOH solution?
(A) 4.0 kg (B) 8.0 kg (C) 16 kg (D) 20 kg (E) 40 kg
18.
When a 1.00-gram sample of limestone was dissolved in acid, 0.38 gram of CO2
was generated. If the rock contained no carbonate other than CaCO3, what was
the percent of CaCO3 by mass in the limestone?
(A) 17% (B) 51% (C) 64% (D) 86% (E) 100%
19.
If 1 mole of O2 oxidizes Fe(OH)2 according to the reaction represented above,
how many moles of Fe(OH)3 can be formed?
…Fe(OH)2 + …O2 + …H2O  …Fe(OH)3
(A) 2 (B) 3 (C) 4 (D) 5 (E) 6
Answers
1 – B 2 – E 3 – D 4 – B 5 – C 6 – B 7 – B 8 – E 9 – B 10 – D 11 – B 12 – C
13 – A 14 – D 15 – C 16 – D 17 –B 18 – D 19 - C