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