Chemistry Final Exam
The formula that a compound ammonium sulfide is _______________.
(NH4)2S
The formula for the compound ammonium sulfate is.
(NH4)2SO4
What is the charge on the cation in CuSO4?
+2
What is the ionic charge on the titanium ion in the ionic compound titanium oxide, TiO2?
+4
What is the ionic charge on the zirconium ion in the ionic compound zirconium oxide, ZrO2?
+4
What is the charge on the anion in CuSO4?
-2
To prevent tooth decay, many communities treat their water supply with a fluoride compound such as CaF2. How many kilograms of CaF2 would be necessary to treat 287 kL of water to a concentration of 1.00 mg/L of CaF2?
.287 kg
Determine the subscript for dichromate in the chemical formula for ammonium dichromate.
0
How many unshared pairs does an atom of boron contain in its Lewis structure?
0
___Ba + ___H2O --> ___Ba(OH)2 + ___H2
0, 2, 0, 0
___(NH4)2CO3 + ___NaOH --> ___Na2CO3 + ___NH3 + ___H2O
0, 2, 0, 2, 2
___Cd(NO3)2 + ___NH2Cl -->
0, 2, CdCl2 + 2NH4NO3
___CH4 + ____________ --> H2O + _________________
0, 2O2 --> 2, CO2
___C2H5OH + ___O2 --> ___CO2 + ___H2O
0, 3, 2, 3
___Fe2(SO4)3 + ___Ba(OH)2 -->
0, 3, 2Fe(OH)3 + 3BaSO4
___C3H6 + ___O2 ---> ___CO + ___H2O
0, 3, 3, 3
What is the molarity of a solution that contains 0.202 mol KCl in 7.98 L solution?
0.0253 M
How many moles of HCl are present in 0.70 L of a 0.33 M HCl solution?
0.23 mol
What is the number of kilograms of solvent in a 0.70 molol solution containing 5.0 grams of solute? (molar mass of solute= 30 g)
0.24 kg
What is the molarity of a solution that contains 125 g NaCl in 4.00 L solution?
0.535 M
How many iron(II) ions combine with oxygen to form iron(II) oxide?
1
What is the expression of molality?
10 mol of solute/ 1 kg of solvent
Determine the subscript for ammonium in the chemical formula for ammonium dichromate.
2
How many electrons are shared in a single covalent bond?
2
How many iron (III) ions combine with oxygen to form iron (III) oxide?
2
___Al + ___Cl2 -->
2, 3, 2AlCl3
___ Na3PO4 + ___ZnSO4 --> ___Na2SO4 + ___Zn3(PO4)2
2, 3, 3, 0
___Au2O3 --> ___Au + ___O2
2, 4, 3
___C3H8 + ___O2 -> ___CO + ___H2O
2, 7, 6, 8
The density of acetylene at STP is 1.17 g/L. The empirical formula of acetylene is CH. Determine the molar masses of acetylene and its molecular formula.
26.2g : C2H2
How many electrons does phosphorous need to gain in order to obtain a noble-gas electron configuration?
3
How many unshared pairs of electrons are in a molecule of hydroiodic acid?
3
What is the total number of covalent bonds normally associated with a single nitrogen atom in a compound?
3
___Mg + ___H3PO4 --> ___Mg3(PO4)2 + ___H20
3, 2, 0, 3
An NaOH solution contains 1.90 mol of NaOH, and its concentration is 0.555 M. What is its volume?
3.42 L
When a mixture of sulfur and metallic silver is heated, silver sulfide is produced. What mass of silver sulfide is produced from a mixture of 3.0 g Ag and 3.0 g S8?
3.5 g Ag2S
How many electrons are shared in a double covalent bond?
4
How many electrons does carbon need to gain in order to obtain a noble-gas electron?
4
What is the total number of covalent bonds normally associated with a single carbon atom in a compound?
4
How many grams of Na2SO4 are needed to prepare 750 mL of a 0.375 M solution?
40 g
How many unshared pairs of electrons are in a molecule of chlorine gas?
6
What is the maximum amount of KCl that can dissolve in 200 g of water? (the solubility of KCl is 34 g/100 g H2O at 20 degrees Celcius)
68 g
___K3PO4 + BaCl2 -->
6KCl+Ba3(PO4)3
What is the mass of Na2SO4 is needed to make 2.5 L of 2.0 M solution? (Na=23 g, S=32 g, O= 16 g)
710 g
Explain what a nonpolar molecule is. Provide an example
A nonpolar molecule has even bonds. The distance between the bonds is equal. Example: CF4
silver + potassium nitrate
Ag +KNO3 --> no reaction
Write the formula for the compoun boron chloride. Why would this name be percieved as incorrect?
BCl3; there is no tri- in front of the chloride
Write the formula for the compound barium oxide
BaO
Name the shapes we studied that automatically make polar molecules. For further bonus, explain why these shapes are automatically polar.
Bent, trigonal pyramidal
1, 6-diminohxane is used to make nylon. What is the empirical formula of this compound if it is 62.1% C, 13.8% H, and 24.1% N?
C3H8N
Calculate the molecular formulas of the compounds having the following empirical formulas and molar masses: C2H5, 58 g/mol; CH, 78 g/mol; and HgCl,236.1 g/mol
C4H10, C6H6, HgCl
The percentage composition of a polymer used for the non-stick surfaces of cooking utensils is 24% C and 76% F by mass. Find the empirical formula.
CF2
Write the correct chemical formula for the compound cadmium phosphate
Cd3(PO4)2
Write the correct chemical formula for the compound cobalt (III) oxide.
Co2O3
Write the correct chemical formula for the compound cobalt (II) oxide.
CoO
Write the formula for the compound cesium telluride.
Cs2Te
Name the compounds CuBr2, SCl2, BaF2. Explain the use or omission of the roman numeral (II) and the prefix di- in each case.
CuBr2- Copper (II) bromide; copper is a stock metal which means that is has more than one charge, so we have to specify which charge it has SCl2- sulfur dichloride; covalent bond, the prefix di- tells us that there are 2 chlorine BaF2- barium fluoride; barium is a non-stock metal which means that it only has one charge
A compound is found to contain 12.95 g N and 37.05 g O. Find the compound's empirical formula. Then, assuming that its actual molar mass is known to be 324 g/mol, find the compound's molecular formula
E: N2O5 M: N6O15
Identify all elements that follow the X-rule format provided by the polyatomic ion rules
Fluorine, Chlorine, Bromine, Iodine
Write a balanced net ionic equation for the following reaction. H3PO4 + Ca(OH)2 --> Ca3(PO4)2 + H2O
H+(aq) + OH-(aq) --> H2O(l)
What is the correct chemical formula for nitrous acid?
HNO2
What is the correect chemical formula for nitric acid?
HNO3
A certain compoun consists of potassium, nitrogen, and oxygen. Hypothesize a possible formula and name for this compound. Explain your reasoning.
KNO2- potassium nitrite KNO3- potassium nitrate
Write the formula of dinitrogen pentoxide
N2O5
Provide the name, formula, and AXE number for a linear molecule
Name- carbon dioxide Formula- CO2 AXE- AX2
Write the formula of diphosphorus tetroxide.
P2O4
Write the formula for the compound rubidium phosphide.
Rb3P
Write the correct chemical formula for the compound tin(II) phosphate
Sn3(PO4)2
Write the formula for the compound strontium sulfide.
SrS
a theory that predicts some molecular shapes based on the idea that pairs of valence electrons surrounding an atom repel each other is called ______________.
VSEPR
What does VSEPR stand for?
Valence Shell Electron Pair Repulsion
Provide the proper formula, name, Lewis structure, and AXE number for a bond experienced between carbo and xenon atoms
Xenon doesn't want to bond; 8 valence electrons
In which of the following is the solution concentration expressed in terms of molarity? a. 10 mol of solute/ 1 L of solution b. 10 g of solute/ 1000 mL of solution c. 10 g of solute/ 1000 g of solution d. 10 mL of solute/ 1 L of solution
a
What is a polar molecule?
a molecule in which the charges are unevenly distributed; H2O, H2S, CH3Cl
The ion formed by an atom of a nonmetal element is a(n) ___________.
anion
In an equation, the symbol for a substance in water solution is ________________.
aqueous (aq)
The mass of the products of the reaction C2H5OH + 3O2--> 2CO2 + 3H2O equals the mass of the reactants because the products are made up of the same _________________ as the reactants.
atoms
In a solution at equilibrium, a. the rate of dissolution is less than the rate of crystallization. b. the rate of dissolution and the rate of crystallization are equal. c. no dissolution occurs d. the rate of dissolution is greater than the rate of crystallization
b
Which of the following substances is less soluble in hot water than in cold water? a. NaNO3 b. CO2 c. NaCl d. KBr
b
Which of the following would be the most concentrated solution? a. 200 g of C12H22O11 b. 100 ppm of C12H22O11 c. 1 mol of C12H22O11 in 1 L of solution d. 1500 ppm of C12H22O11 in water
c
The A in the AXE number of any molecule refers specifically to the _________________.
central atom
A catalyst for a reaction is indicated by a ________ written over the arrow in a chemical equation.
chemical formula
Name the following acid: HClO3
chloric acid
In the compound HCl, the atom of the element _____________ carries a partial negative charge.
chlorine
Name the following acid: HClO2
chlorous acid
Name the compound Co2O3
cobalt (III) oxide
The fact that a compound forms a molecule automatically identifies it as containing __________ bonds.
covalent
Which of the following expresses concentration? a. molality b. parts per million c. molarity d. all of the above
d
The reaction 2HgO(s) --> 2Hg(l) + O2(g) is classified as a(n) _________ reaction
decomposition
Name the compound N2Se4
dinitrogen tetraselenide
Name the compound P2Se5
diphosphorus pentaselenide
In a(n) _________________ reaction, ions of two compounds wxchange places in aqueous solution to form new compounds.
double replacement
Name the following acid: HBr
hydrobromic acid
Name the following acid: HF
hydrofluoric acid
In the compound HCl, the atom of the element ____ carries a partial positive charge.
hydrogen
As the difference between electronegativity values of two elements joined by a bond ____, the degree of the polarity of the bond increases
increases
What is the proper name for FeO2?
iron (IV) oxide
In an ionic bond, the cation is alomst always formed from which type of element?
metal
Name another bond type besides ionic and covalent.
metallic
Provide the name, formula, and AXE number for a bent molecule
name- dihydrogen monoxide formula- H2O AXE- AX2E2
What is the limiting reagent when 150.0 g of nitrogen reacts with 32143 mg of hydrogen in the formation of ammonia?
neither are limiting reagents
If the difference in elctronegativity values between two elements is 0.1 or lower, they will most likely form a(n) ___________ covalent bond.
non-polar
Give the shape of the molecule of SH6
octahedral
Give the proper name of Os(CO3)3
osmium (VI) carbonate
Which energy level is occupied by valence electrons?
outmost energy level
As the difference between electronegativity values of two elements joined by a bond decreases, the less ___________ a bond will become.
polar
If the difference in electronegativity values between two elements if 1.9, they will most likely form a(n) _______________ covalent bond.
polar
An electrically charged group of two or more bonded atoms that function as a single ion is called a(n) _________________ ion
polyatomic
Any compound that contains both covalent and ionic bonds must have at least one _________________ ion.
polyatomic
The reaction Mg(s) + 2HCl(aq) --> H2(g) + MgCl2(aq) is classified as a(n) ______________ reaction.
single replacement
In the chemical reaction 2Cr(s) + 3O2(s) --> 2CrO3(s), two chromium atoms combine with ________________ oxygen atoms
six
Ions that are present in solution in which a reaction is taking place but that do not participate in the reaction are called __________________.
spectator
The reaction 2Mg(s) + O2(g) --> 2MgO(s) is classified as a(n) ____________ reaction.
synthesis
The molecular shape of CBr4 is classified as _____________.
tertrahedral
The molecular shape of CHBr3 is classified as ______________.
tetrahedral
Because of the unique electron configuration of boron, VSEPR theory predicts that the molecular shape of BF3 is classified as ____________________.
trigonal planar
The molecular shape of NH3 is classified as _______________.
trigonal pyramid
The molecular shape of PCl3 is classified as _____________________.
trigonal pyramidal
A covalent bond in which two atoms share three pairs of electrons is called a(n) ____________ bond.
triple
A nonbonding pair of electrons in the valence shell of an atom is called a(n) ______________ pair.
unshared
An electron that occupies the outermost energy level of an atom is known as a(n) _______________ electron.
valence
