Question 1 of 23 -2.0/ 0.0 Points
Which of the following species is a molecular element?
A.Sodium
B.Neon
C.Potassium
D.Carbon Dioxide
E.None of the above
Answer Key: E
Question 2 of 23 2.0/ 2.0 Points
There are exactly 2.54 centimeters in 1 inch. When using this conversion factor, how many significant figures are you limited to?
A.1
B.3
C.Ambiguous
D.Depends on if you are using it in multiplication/division or addition/subtraction
E.Infinite number of significant figures
Answer Key: E
Question 3 of 23 0.0/ 2.0 Points
How many low dose 62 mg aspirin tablets can be made from 1.21 kg of aspirin?
A.1.5 × 103 tablets
B.1.21 × 10^3 tablets
C.1.21 × 104 tablets
D.2.0 × 104 tablets
E.1.5 × 104 tablets
Answer Key: D
Question 4 of 23 0.0/ 2.0 Points
Which statement below is NOT consistent with the nuclear theory of the atom as proposed by Rutherford?
A.Electrical charge is a fundamental property of protons and electrons in which like charges repel and opposite charges attract.
B.Most of the atom's mass and all of its positive charge is contained in a small core called the nucleus.
C.Most of the volume of the atom is empty space occupied by tiny, negatively charged electrons.
D.There are as many electrons outside the nucleus as there are protons inside the nucleus in a neutral atom.
E.All of the above statements are consistent.
Answer Key: A
Question 5 of 23 0.0/ 2.0 Points
All of the following statements about different elements are true EXCEPT:
A.Sulfur is considered a non-metal.
B.Manganese is a transition metal.
C.Iodine is a halogen.
D.Krypton is one of the noble gases.
E.Barium is an alkali metal.
Answer Key: E
Question 6 of 23 2.0/ 2.0 Points
Which of the following is NOT a correct name, symbol combination?
A.beryllium, Be
B.phosphorus, P
C.sulfur, Sr
D.manganese, Mn
E.iron, Fe
Answer Key: C
Question 7 of 23 0.0/ 2.0 Points
Cr is a member of which family?
A.noble gases
B.alkaline earth metals
C.halogens
D.alkali metals
E.none of the above
Answer Key: E
Question 8 of 23 2.0/ 2.0 Points
How many neutrons are present in C-14?
A.8
B.14
C.6
D.12
E.None of the above
Answer Key: A
Question 9 of 23 2.0/ 2.0 Points
Ions are formed when atoms
A.gain or lose neutrons.
B.gain or lose electrons.
C.gain or lose protons.
D.Each of these results in ion formation.
E.None of these results in ion formation.
Answer Key: B
Question 10 of 23 2.0/ 2.0 Points
Group 2A elements are also called:
A.noble gases.
B.alkaline earth metals.
C.alkali metals.
D.halogens.
E.none of the above.
Answer Key: B
Question 11 of 23 2.0/ 2.0 Points
How many moles of H2 can be made from complete reaction of 2.0 moles of Al? Given: 2 Al + 6 HCl → 2 AlCl3 + 3 H2
A.4.5 moles
B.3.0 moles
C.9.0 moles
D.2.0 moles
E.none of the above
Answer Key: B
Question 12 of 23 2.0/ 2.0 Points
What is the theoretical yield of a reaction if 32.0 grams of product were actually produced from a reaction that has a 88% yield?
A.3.52
B.28.2
C.36.4
D.352
E.none of the above
Answer Key: C
Question 13 of 23 2.0/ 2.0 Points
Consider the following generic chemical equation: 2A + 5B → C + 3D If you react 4 units of A with 10 units of B, which statement is TRUE?
A. Substance B will be the limiting reactant.
B.Substance C cannot be formed from this reaction.
C.There is just enough of A and B so that everything reacts completely.
D.Substance A will be the limiting reactant.
E.none of the above
Answer Key: C
Question 14 of 23 0.0/ 2.0 Points
What type of a reaction occurs when a barium chloride solution is mixed with a silver nitrate solution?
A.oxidation-reduction
B.precipitation
C.gas evolution
D.acid-base neutralization
E.no reaction
Answer Key: B
Question 15 of 23 2.0/ 2.0 Points
An aqueous solution is:
A.water with another compound dissolved in it.
B.any liquid with another compound dissolved in it.
C.an ionic compound with water dissolved in it.
D.water with a molecular compound dissolved in it.
E.none of the above
Answer Key: A
Question 16 of 23 0.0/ 2.0 Points
Which of the following compounds is INSOLUBLE?
A.lithium phosphate
B.calcium sulfate
C.magnesium nitrate
D.magnesium iodide
E.none of the above
Answer Key: B
Feedback: Feedback: See section 7.5 of the text (table 7.2).
Question 17 of 23 2.0/ 2.0 Points
When water is heated, bubbles form in the water. Is this evidence of a chemical reaction? Why?
A.Yes, the formation of a gas is proof a new compound has been made.
B.Yes, the formation of a gas is evidence of a chemical reaction.
C.No, boiling water is a physical change.
D.No, the formation of gas bubbles is a secondary chemical reaction which is ignored.
E.None of the above
Answer Key: C
Question 18 of 23 0.0/ 2.0 Points
If 2.01 × 1023 atoms of an element from Group IIA of the periodic table has a mass of 29.3 grams, this element is most likely:
A.Sr
B.Mg
C.Ca
D.Na
E.Ba
Answer Key: A
Question 19 of 23 0.0/ 2.0 Points
The empirical formula of a compound:
A.is the same as the molecular formula.
B.indicates the simplest ratio of atoms in the compound.
C.describes the mass relationships in a molecule.
D.indicates the structure of the molecule.
E.none of the above
Answer Key: B
Question 20 of 23 2.0/ 2.0 Points
How many atoms are in 5.80 moles of He?
A.3.49 × 1024
B.1.03 × 1023
C.4.00
D.6.02 × 1023
E.none of the above
Answer Key: A
Question 21 of 23 2.0/ 2.0 Points
What is the name of HNO3?
A.Nitrous acid
B.Nitric acid
C.hydronitrous acid
D.hydronitric acid
E.none of the above
Answer Key: B
Question 22 of 23 0.0/ 2.0 Points
How many nitrogen atoms are in the formula Cu(NO3)2?
A.1
B.9
C.6
D.2
E.none of the above
Answer Key: D
Question 23 of 23 2.0/ 2.0 Points
How many moles are in 6.80 grams of CO?
A.0.037
B.5.5
C.4.1
D.0.24
E.6.02 x 1023
Answer Key: D
Question 1 of 13 4.0/ 5.0 Points
Give an example of a molecular compound and an element.
Molecular compound: H2O
An Element: H2
Question 2 of 13 5.0/ 5.0 Points
There are exactly 2.54 centimeters in 1 inch. When using this conversion factor, how many significant figures are you limited to?
you are left with an infinite number of significant figures
Question 3 of 13 5.0/ 5.0 Points
How many low dose 62 mg aspirin tablets can be made from 1.21 kg of aspirin?
62 mg x (1kg/1.0 x10^6 mg)=6.2 x 10^-5 kg aspirin tablets
1.21kg aspirin / 6.2 x 10^-5 kg aspirin tablet= 1.9x10^4 tablets
Question 4 of 13 5.0/ 5.0 Points
Describe the nuclear theory of the atom as proposed by Rutherford.
The theory is an atom as having a central positive nucleus surrounded by negative orbiting electrons.
Question 5 of 13 5.0/ 5.0 Points
What are some properties of noble gases. What is significant about their outermost shell?
The noble gases are He, Ne, Ar, Kr, Xe, Rn. All of these gases are monatomic. They boil at low temperatures as only dispersion forces act between the atoms.
The outer shell have the maximum number of electrons possible.
Question 6 of 13 3.0/ 5.0 Points
Describe the difference between theories and laws.
A theory is a statement based on a collection of ideas, observations and hypotheses but can still be proven wrong.
A law is a statement based on a collection of ideas, observations, and hypotheses that will most likely not be proven wrong and is considered a fact,
Question 7 of 13 5.0/ 5.0 Points
How many moles of H2 can be made from complete reaction of 2.0 moles of Al? Given: 2 Al + 6 HCl → 2 AlCl3 + 3 H2
you would get 3 moles of H2
Feedback: The ratio of moles Al to moles H2 come from the balanced equation.
2.0 mol Al x (3 mol H2/2mol Al)=3.0 moles H2
Question 8 of 13 5.0/ 5.0 Points
What information does an empirical formula of a compound tell us?
An empirical formula only gives the smallest whole-number ratio of each type of atom in a compound,not the specific number of each type of atom in a molecule.
Question 9 of 13 0.0/ 5.0 Points
How many atoms are in 5.52 moles of Ca?
8.2x10^22
Comment: must show all calculations
Question 10 of 13 4.0/ 5.0 Points
An object with a mass of 9.248 g is dropped into 44.6 mL of water. The volume after the object is dropped is 48.8mL. What is the density of the object? (show all calculations)
(48.8 mL - 43.9 mL) = 4.9 mL (rise in volume)
Mass / Volume = Density
9.248 g / 4.9 mL = 1.9 g/mL
Model Short Answer:
Vobject =Vfinal -Vinitial
Vobject= 48.8 ml - 44.6 ml=4.2 ml
Density = mass/volume
Density= 9.248 g/4.2 ml= 2.2 g/ml
Question 11 of 13 5.0/ 5.0 Points
Write the chemical formula for each of the following ionic compounds: Copper (I) Chloride, Silver (I) Sulfate, Calcium Nitrate
Copper (I) Chloride = CuCl
Silver (I) Sulfate = Ag2SO4
Calcium Nitrate = Ca(NO3)2
Question 12 of 13 7.0/ 15.0 Points
A) What is the limiting reactant for the following reaction given we have 3.5 moles of HCl and 1.4 moles of Ca(OH)2? Reaction: 2HCl + Ca(OH)2 → 2H2O + CaCl2
B) In an actual experiment 0.5 g of CaCl2 is produced. What is the percent yield?
(show all calculations)
A) the limiting reactant would be 3.5 moles of HCI
B) mole of Ca = 40.1 grams
1 mole of Cl2 = 2 * 35.5 = 71.0 grams of Cl2
So, 40.1 + 71.0 = 111.1 grams of CaCl2 should have been produced!!
Since only 0.5 grams of CaCl2 was produced, the percent yield =
% yield = (0.5 ÷ 111.1) * 100 = 45%
Model Short Answer: 3.5 moles HCl x (1mole CaCl2/2 mole HCl)= 1.8 moles CaCl2
1.4 moles Ca(OH)2 x (1 mole CaCl2/1mole Ca(OH)2)= 1.4 moles CaCl2
Ca(OH)2 is the limiting reactant.
Question 13 of 13 0.0/ 15.0 Points
Reaction: 3Ca(NO3)2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4)2
A) What is the limiting reactant for the following reaction given we have 3.4 moles of Ca(NO3)2 and 4.4 moles of Li3PO4?
B) What is the theoretical yield (in grams) of Ca3(PO4)2
A) limiting reactant Ca(NO3)2
B) Ca3(PO4)2 = 310.176722 g
Comment: Must show all calculations. You have to find out how many moles of Ca3(PO4)2 are made from each reactant:
3.4 mol Ca(NO3)2 x (1 mol Ca3(PO4)2 /3mol Ca(NO3)2) = 1.13 mol Ca3(PO4)2
4.4 mol Li3PO4 x (1 mol Ca3(PO4)2 /2molLi3PO4) = 1.13 mol Ca3(PO4)2 =2.2 mol Ca3(PO4)2
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