Suppose you are building bird houses. The bird houses require
ten nails and four pieces of wood each. Which of the following is not an
exact relationship (ratio) between the number of nails and the number
of pieces of wood you would need to build more than one birdhouse?
A) 4 boxes of nails, 100 pieces of wood
Consider the generic reaction A + B —? C. This is an example of a
In an acid-base reaction, a weak acid would not form as much water as the same amount of strong acid.
Calculate the number of atoms in 42.6 amu of nitrogen.
E) 1, exactly
What is a decomposition reaction?
A) One reactant yielding product(s)
If you wanted to create laboratory workbooks and you had 15
front covers, 21 back covers and 64 blank sheets of paper, how many
workbooks could you assemble if 1 workbook = 1 front cover + 5 blank
sheets + 1 back cover?
How many grams of iron (III) chloride may be formed when 43g of iron and 160g of Cl2 are reacted? 2Fe(s) + 3Cl2(s)-> 2FeCl3
It is possible for only an oxidation to occur in a reaction.
Oxidation must occur with reduction.
Which of the following reactions could be classified as a double-displacement reaction?
A) Pb(NO3)2 (aq) + H2S (aq) --? 2HNO3 (aq) + PbS (s) (OK)
How many grams of hydrogen are required to form 180 grams of water?2H2 + O2 -> 2H2O
Calculate the mass, in grams, of 1.51 mol of carbon tetrachloride, CCl4.
It is not important to balance a chemical equation in order to see the number relationships.
In order to know how much of each substance reacts, it is very important to balance the equation.
n an oxidation-reduction reaction,
C) metals lose electrons.
In the reaction: 2Fe(s) + 3Cl2(g) ->2FeCl3(s) (same as question 8), if 43 grams of iron were reacted, how many grams of Cl2 would be needed?
If 65g of iron react with 170g of Cl2, and the actual yield of FeCl3(s) was 43g, what would the percentage yield be? 2Fe(s) + 3Cl2(g) ->2FeCl3(s)
A compound containing magnesium and oxygen contains 43.2% Mg by mass. What is a possible formula for the compound?
What mass of oxygen contains the same number of atoms as 32.0 g of sulfur?
A) 16.0 g
What evidence is there that ions separate in solution?
E) Charge may be carried by such a solution.
A gross is a dozen dozen, or 144 items. Suppose you have 14
1/2 gross of ping-pong balls in your warehouse. How many ping-pong balls
On the basis of the general solubility rules, which of the following compounds should be insoluble in water?
What is the mass of nitrogen atoms in amu's? 1.2 x 10-24
C) 1.7 x 1025
Which of the following statements is false?
C) If a reactant is left over after a reaction, it was the limiting reactant.
Which of the following is not one of the four "driving forces" that pull reactants to form products during chemical reactions?
A) Formation of a product.
In one word, why do we use average atomic masses for the elements?
On the basis of the solubility rules, which of the following should be soluble in water?
If 1000 HCl units and 1000 HCN units were dissolved in water,
the relative amounts of species in solution would be shown as _____(HCN
is a weak acid):
E) H+< Cl-< HCN < HCl
A) H+ ? Cl-> HCN > CN-
A store has oranges which are, on average, 2.3 oranges per
pound. If navel oranges cost $0.79/lb, how many oranges (to the nearest
whole orange, of course) will $5.00 buy?
If 65g of iron react with 170g of Cl2, how many grams of FeCl3(s) product could be formed? 2Fe(s) + 3Cl2(g) ->2FeCl3(s)
What is the net charge of a precipitate formed by two aqueous solutions?
D) Neutral, because an insoluble salt compound is formed.
Which two compounds have the same empirical formula?
D) C2H5OH and C6H18O3
Which of the following reactions could be classified as an oxidation-reduction reaction?
B) Zn (s) + 2 HCl (aq) --? H2 (g) + ZnCl2 (aq)
How many moles of K2CO3 would be formed by the complete reaction of 0.75 moles of KO2 in the reaction: 4KO2(s) + 2CO2(g) -> 2K2CO3(s) +3O2?
From the number of grams of a single product formed in a balanced chemical reaction, you may determine
D) How many total grams of all reactants were used up.
Knowing the percent yield and the actual yield (in grams), one could determine:
B) B & C
Calculate the mass percent composition of calcium in Ca(NO3)2.
Determine the number of vanadium atoms in 1.2 x 10-24 g of vanadium.
C) 1.4 x 1018
In the reaction: 2Fe(s) + 3Cl2(g) ->2 FeCl3(s), if 43 grams of iron were reacted, how many moles of iron were reacted?
What type of reaction is responsible when a free element is converted to a compound?
A compound with molar mass of approximately 80 g/mol has the
following composition (mass percent): C: 75.9%, H: 6.4%, and N: 17.7%.
What is its molecular formula?
In the reaction: 2Fe(s) + 3Cl2(g) ->2FeCl3(s) (same as question 8), if 43 grams of iron were reacted, how many grams of FeCl3 could be produced?
The mass of hydrogen is 1g/mol, so in the reaction:2H2(g) + C(s) -> CH4(g), 2 grams of hydrogen will fully react with one gram of carbon.
A certain acid-base reaction resulted in the formation of the salt, RbNO3, in addition to water. Which acid-base pair could have been used?
E) RbOH, HNO3
Eleven moles of water are produced by the reaction of hydrogen and oxygen: 2H2 + O2 -> 2H2O. How many moles of oxygen were used?
How many moles of water may be formed when 12 moles of
hydrogen gas are mixed with 11 moles of oxygen gas and are allowed to
react? 2H2 + O2 --> 2H2O
Which compound has the highest percent by mass magnesium?
_______ ions are those that do not participate directly in a reaction.
If 65g of iron react with 170g of Cl2, which reactant is limiting? 2Fe(s) + 3Cl2(g) ->2FeCl3(s)
Which has the greatest percent by mass of nitrogen: 100 g of ammonia, or 1 kg of ammonia?
A) They both have the same mass percent composition of nitrogen.
Which compound has a molar mass closest to 100 g/mol?
When oxalate ion is mixed with a calcium sulfate solution,
solid calcium oxalate is formed. Identify the net ionic equation for
A) Ca2+ (aq) + C2O42-(aq) --? CaC2O4 (s) (OK)
magnesium were to react with the non-metal fluorine, how many electrons
would each Mg atom lose, and how many would each F atom gain?
A) Mg: 2; F: 1
Which statement about empirical formulas is false?
B) No two compounds may have the same empirical formula.
Calculate the molar mass of lead(II) nitrate (in g/mol).
Which is a valid, general definition of a salt?
B) The compound besides water that is formed in an acid-base reaction.
Fill in the blanks with the words or phrases that make the
most sense: "If a certain sample of an element contains ____ atom(s),
the sample weighs _____."
B) Avogadro's number of ... the molar mass
Given the balanced reaction: CCl4 + 2HF -? 2HCl + CCl2F2, identify which statement is incorrect.
E) A product mixture containing 20g of HCl indicates 20g of HF reacted.
a gross of ping-pong balls weighs 3 kilograms. A client wants to fill
his truck with ping-pong balls, and his truck will transport only 1000
kg. How many ping-pong balls may he carry?
In the reaction 2Fe(s) + 3Cl2(g) -> 2FeCl3(s), Which of the following statements is incorrect?
C) 6 moles of chlorine gas will produce 9 moles of FeCl2 (s).