Term 2 Chem 1120 Chapter 3&4 Review
The oxidation state of iodine in IO3- is:
+5
the oxidation state of chlorine in ClO3-
+5
Potassium forms an oxide containing 1 oxygen atoms of potassium. what is the coefficient of oxygen in the balanced equation for the reaction of potassium with oxygen to form this oxide?
1
how many moles of hydrogen sulfide are contained in 44.4 g sample of this gas?
1.30 mol
SO2 reacts with H2S as follows: 2H2S + SO2 --> 3S + 2H2O
10.6 g of sulfur are formed
What mass of solute is contained in 256 mL of a 0.944 M ammonium chloride solution?
12.9 g
the molar mass of the compound formed by sodium and selenium is
124.9 g/mol
one molecule of a compound weighs 2.50*10^22g. the molar mass of this compound is:
151 g/mol
what is the mass of a 4.110 mol sample of sodium hydroxide
164.4 g
a 230.0 mL sample of a 0.275 M solution is left on a hot plate overnight; the following morning the solution is 1.41 M. What volume of solvent has evaporated from the 0.275 M solution?
185.1 mL
Determine the coefficient for O2 when the following equation is balanced in standard form (smallest whole numbers) C6H14 +O2 ---> CO2 + H2O
19
Determine the coefficient for O2 when the following equation is balanced in standard form(smallest whole numbers.) C6H14 + O2 --> CO2 + H2O
19
Balance this equation using the smallest possible integers s + HNO3 --> H2SO4 + NO2 + H2O
2
Consider the following unbalance oxidation-reduction reaction: Fe2 + Cl2 --> Fe3+ + Cl- in the balanced equation, the number of electrons transferred is
2
How many grams of NaCl are contained in 350. mL of 0.115M solution of sodium chloride>
2.35 g
What volume of 18 M sulfuric acid must be used to prepare 1.80 L of 0.205 M H2SO4?
21 mL
Calculate the molar mass of barium nitrite
229.35 g/mol
in the balanced molecular equation for the neutralization of sodium hydroxide with sulfuric acid, the products are: a. NaSO4 + H2O b. NaSO3 + 2H2O c. 2NaSO4 + H2O d. Na2S + 2H2O e. Na2SO4 + 2H2O
Na2SO4 + 2H2O
A compound of sulfur and fluorine is found to contain 25.24% by mass of sulfur. If the molar mass of the compound is 254.11 g/mol, what is its molecular formula?
S2F10
The molecular formula always represents the total number of atoms of each element present in a compound
True
How many of the following salts are expected to be insoluble in water? - sodium sulfide , barium nitrate, ammonium sulfate, potassium phosphate none 1 2 3 4
none
what is the molar mass of butanol?C4H9OH
74.12 g/mol
What mass of calcium chloride is needed to prepare 4.600 L of a 1.53 M Solution?
781 g
A hypothetical element consists of two isotopes of masses 79.95 amu and 81.95 amu with abundacnes of 31.3% and 68.7% respectively. What is the average atomic mass of this element?
81.3 amu
What is the sum of the coefficient of the following equation when it is balanced using smallest whole numbers?
9
Vitamin C contains the elects C, H, and O. it is known to contain 40.9% C and 4.58& H by mass. The molar mass of vitamin C has been found to be about 180 g/mol. The molecular formula for vitamin C is:
C6H8O6
the empirical formula of styrene is CH; its molar mass is 104.1 g/mol What is the molecular formula of styrene?
C8H8
Given the equation 3A + B --> C + D you react 2 moles of A with 1 mole of B. which of the following is true?
A is the limiting reactant because you need 3 moles of A and have 2.
which if the following equations correctly describes the combustion of CH4 and O2 to produce water and carbon dioxide(CO2)
CH4 + 2O2 --> CO2 + 2H2O
in the reaction 2Ca + O2 --> 2CaO which species is oxidized?
Ca
consider an aqueous of calcium nitrate added to an aqueous solution of sodium phosphate. What is the formula of the solid formed in the reaction? a. Ca(PO4)2 b. CaPO4 c. Ca3(PO4)2 d. NO3- e. AgCl
Ca3(PO4)2
the balanced complete ionic equation which of the following terms? a. 2Ba2+ b. Cl- c. 2Ag+ d. NO3- e. AgCl
2Ag+
which of the following equations in not balanced?
2KClO3 ---> 2KCl + 3/2 O2
when sodium chloride and lead(II) nitrate react in an aqueous solution, which of the following terms will be present in the balanced molecular equation?
2NaNO3
A sample of ammonia has a mass of 89.9 g. How many molecules are in this sample?
3.8*10^24 molecules
what is the molar mass of Ca3(PO4)2
310.18 g/mol
The net ionic equation for the reaction of calcium bromide and sodium phosphate contains which of the following species?
3Ca2+
A 72.5 g sample of SrCl2 is dissolved 112.5 mL of solution. Calculate the molarity of this solution
4.07 M
what mass of NaOH is required to react exactly with 25.0 mL of 2.2 M H2SO4?
4.4 g
Consider the element indium, atomic number 49 atomic mass 114.8 grams. the nucleus of an atom-112 contains
49 protons, 63 neutrons
how many atoms of hydrogen are present in 7.85 g of water ?
5.25 * 10 ^23
What is the mass of 5 atoms of copper in grams?
5.28*10^-22
Balance the following oxidation-reduction using the oxidation number method: Cr + Cl2 ---> Cr3+ + Cl-
6
Balance this equation using the smallest possible integers, NO + NH3 --> N2 + H2O what is coefficient of the water?
6
what is the coefficient for water when the following equation is balanced? As(OH)3 + H2O --> As2(SO4)3 + H2O
6
What is the coefficient for oxygen when the following equation is balanced?
7
naturally occurring copper exists in two isotopic forms: 63Cu and 65Cu. The atomic mass of copper is 63.55 amu. What is the approximate natural abundance of 63Cu?
70%
The man who discovered the essential nature of acids through solution conductivity studies is
Arrhenius
A hydrocarbon (a compound consisting solely of carbon and hydrogen) is found to be 85.6 % carbon by mass. What is the empirical formula for this compound?
Ch2
when solutions of cobalt(II) chloride acid react, which of the following terms will be present in the net ionic equation?
CoCO3
in balancing an equation, we change the ________ to make the number of atoms on each side of the equation balance.
Coefficients of compounds
An acid is a substance that produce OH- ions in water.
False
The concentration of a salt water solution that sits in an open beaker decreases over time
False
when balancing a chemical equation, it is generally best to start with the least complicated molecules
False
In which of the following does nitrogen have an oxidation state of +4?
NO2
Phosphoric acid can be prepared by reaction of sulfur acid with phosphate rock according to the equation Ca3(PO4)2 + 3H2SO4 --> 3CaSO4 + 2H3PO4 supposed the reaction is carried out starting with 123 g of Ca3(PO4)2 and 90.2 g of H2SO4. which substance is the limiting reactant?
H2SO4
when solutions of acetic acid and sodium hydroxide react, which of the following are not present in the net ionic equation
I and III hydrogen ion & sodium ion
When solutions of carbonic acid and magnesium hydroxide react, which of the following are not present in the net ionic equation?
I and IV. hydrogen ion & hydroxide ion
In writing the complete ionic equation for the reaction - if any- that occurs when aqueous solutions of KOH and Mg(NO3)2 are mixed, which of the following would not be written as ionic species?
Mg(OH)2
the _____ in a balanced equation represent numbers of molecules
coefficients
the percent yield is a ratio of the ______ yield to the ________ yield, multiplied by 100%
actual, theoretical
the percent yield is a ration of the _____ to the ______ yield, multiplied by 100%
actual, theoretical
which of the following compounds has the same percent composition by mass as styrene, C8H8
all of these: Acetylene C2H2 Benzene C6H6 Cyclobutadiene C4H4 A-ethyl naphthalene C12H12
Which of the following aqueous solutions contains the greatest number of ions?
b. 300.0 mL of 0.10 M caCl2
An unknown substance dissolves readily in water not in benzene ( a nonpolar solvent). Molecules of what type are present in the substance?
b. polar
Soluble ionic compounds contains the hydroxide ion are called strong
bases
1.00 mL of a 3.55*10^-4 M solution of oleic acid is diluted with 9.00 mL of petroleum ether, forming solution. Then 2.00 mL of solution A is diluted with 8.00 mL of petroleum ether, forming solution B. What is the concentration of solution B?
e. 7.10 * 10 ^-6 M
Which of the following salts is insoluble in water? a. Na2S b. K2CO3 c. Pb(NO3)2 d. CaCl2 e. all of these are soluble in water
e. all of these are soluble in water.
when solutions of acetic acid and magnesium hydroxide react, which of the following are spectator ions? a. hydrogen ion b, acetate ion c. magnesium ion d. hydroxide ion e. none of these
e. none of these
A chemical that changes color at the endpoint of a reaction is called a colorimeter
false
to balance a chemical equation, the coefficients must not be changed
false
the reactant with the highest molar mass is always the limiting reactant
fasle
The limiting reactant in a reaction
has the lowest ratio of moles available/coefficient in the balanced equation
When solutions of acetic acid and sodium hydroxide react, which of the following are not present in the complete ionic equation?
hydrogen ion
in order to determine the molecular formula from the empirical formula we must know the
molar mass
The limiting reactant in a reaction
none of the above - the reactant for which is the least amount in grams - the reactant which has the lowest coefficient in a balanced equation - the reactant for which there is the most amount of grams - the reactant for which there is the fewest number of moles
if x equals 2, the coefficient z equals: xP4O6 + yH2O --> zH3PO3
none of these
Balanced chemical equation imply which of the following?
numbers of atoms are conserved in chemical change
all of the following reactions 2Al + 3Br2 --> 2AlBr3 2Ag2O ---> 4Ag + O2 Ch4 + 2O2 --> CO2 + 2H2O a. oxidation - reduction b. combustion c. precipitation d. A and B e. A and C
oxidation - reduction
Equal masses (in grams) of hydrogen gas and oxygen gas are reacted to form water. Which substance is limiting ?
oxygen gas is limiting
in a chemical equation, the ______ are written on the left side of the arrow, and the _____ are written on the right side of the arrow.
reactants and products
a ___________ electrolyte dissociates to a great extent in an aqueous solution
strong
the _____ in a chemical equation represent the number of atoms in a particular molecule or formula unit
subscripts
wPCl5 + xH2O --> yPOCL3+ zHCl
the equation is balanced when: w=1 x=1 y=1 z=2
Which of the following do you need to know to be able to calculate the molarity of a salt solution?
the mass of salt added the molar mass of the salt the total volume of the solution
In the reaction 2Cs + Cl2 --> 2CsCl, Cl2 is
the oxidizing agent
in the reaction C + O2 --> CO2 carbon is
the reducing agent
the reactant which when used up completely can produce the least amount of product is the limiting reactant
true
suppose you are given the percent by mass of the elements in a compound and you wish to determine the empirical formula. which of the following is true?
you must convert percent by mass to relative numbers of atoms
in the reaction Zn + H2SO4 --> ZnSO4 + H2 , which if any element is oxidized?
zinc
