Molarity, Acid Base Answers

Chemical Reactions Answers

1.     Classify the following chemical reactions as Synthesis (S), Decomposition (D), Combustion (C), Single displacement (SD), or Double displacement (DD).

a)      2 H₂O → 2 H₂ + O₂ ____D____

b)     8 Fe + S₈ → 8 FeS ____S____

c)      AgNO₃ + NaCl → AgCl + NaNO₃ ____DD____

d)      Zn + H₂SO₄ → ZnSO₄ + H₂ ___SD_____                                                   

               e)      CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g) ____C____

2. Complete and balance (if necessary) the following chemical equations 

a) C₆H₁₂O₆ + ___6___O₂ à ___6__CO₂ + ___6___H₂O

b) ___2___C₇H₁₄ + ___21___O₂ à ___14____CO₂ + ____14___H₂O

The Mole Concept Molar Mass Answers

1. What is the molar mass of MgO?

            40.3 grams/mole

2. Determine the molar mass for the following elements:

Ca                                                              Xe                                                             K

40.08 g Ca                                                131.29 g Xe                                              39.10 g K

Fe                                                              Au                                                             O

55.85 g Fe                                                 196.97 g Au                                              16.00 g O

3. Determine the molar mass for the following molecules/compounds

NaCl                                                          H₂O                                                           O₂

22.99 + 35.45                                            2(1.01) + 16.00                                         2(16.00)

58.44 g NaCl                                            18.02 g H₂O                                             32.00 g O₂

Fe₂O₃                                                        Na₂O                                                         Cl₂

2(55.85) + 3(16.00)                                  2(22.99) + 16.00                                       2(35.45)

159.70 g Fe₂O₃                                         61.98 g  Na₂O                                          70.90 g Cl₂

_4. Determine the mass of the following samples

2 moles Co                                                5 moles H₂                                                2.1 moles H₂O

2 mol Co (58.93 g Co/1 mol Co)                                   5 mol H₂ (2.02 g H₂/1 mol H₂)                                         2.1 mol H₂O (18.02 g H₂O /1 mol H₂O)

117.86 g Co                                              10.10 g H₂                                                 37.84 g H₂O

5. Determine the number of moles in the following samples

54.2 g N₂                                                   202.2 g MgO                                             519.3 g FeCl₃

54.2 g N₂ (1 mol N/28.02 g N₂)                                                202.2 g MgO (1 mol MgO/40.31 g MgO)                               519.3 g FeCl₃(1 mol N/162.20 g FeCl₃)

1.93 mol N₂                                              5.02 mol MgO                                         3.20 mol FeCl₃

6. Determine how many atoms/molecules in the following samples

1.32 moles Si

1.32 moles Si (6.022X10²³ atoms/1 mol Si)

7.95X10²³ atoms Si

7.29 mol CO

7.29 mol CO(6.022X10²³ molecules/1 mol CO)

4.39X10²⁴ molecules CO

712.4 g AuCl

712.4 g AuCl (1 mol AuCl/232.42 g AuCl) (6.022X10²³ molecules/1 mol AuCl)

1.85X10²⁴ molecules AuCl

Chemical Bonds Answers

1.     Which type of bonding would be expected between S and Cs?

a)     Polar covalent

b)    Ionic

c)     Non polar covalent

d)    Metallic

2.     Molecules usually involve which type of atoms?

a)     Metals and non metals

b)    Two non metals

c)     Water and sodium

d)    Two metals

3.     Which of the following contains a covalent bond?

a)      Li₂O

b)     NO₃

c)      NaCl

d)      MgO

4.     In a crystalline compound, each anion is surrounded by _____.

a)      Positive ions

b)     Negative ions

c)      Other anions

d)      Positive anions

5.     A bond in which electrons are shared equally is known as _____.

a)      Non polar covalent

b)     Polar covalent

c)      Ionic

d)      Metallic

6.     The model for metallic bonding is known as _____.

a)      The Rutherford model

b)     The electron cloud model

c)      The quantum model

d)      The electron sea model

7.     Of the following, the most likely pair to form an ionic bond is _____.

a)      A noble gas and a metal

b)     A halogen and an alkali metal

c)      A transition metal and an alkaline earth metal

d)      A lanthanide and an actinide

Atomic Structure Answers

Periodic Table Answers

 1.     The rows of the periodic table are called

a)    Groups

b)   Periods

c)    Families

d)   Classes

2.     As you move from left to right across the periodic table

a)    Atomic radius increases

b)   Atomic radius decreases

c)    Ionization energy decreases

d)   Electronegativity decreases

3.     Which of the following are properties of the non-metals?

a)    Donate electrons, poor conductors of heat and electricity

b)   Gain electrons, good conductors of heat and electricity

c)    Donate electrons, good conductors of heat and electricity

d)   Gain electrons, poor conductors of heat and electricity

4.     Where do you expect to find the smallest atoms in the periodic table?

a)    Top and left-hand side

b)    Top and right-hand side

c)    Bottom and left-hand side

d)   Bottom and right-hand side

5.     Common antiseptics and disinfectants belong to which family?

a)    Alkali metals

b)   Transition metals

c)    Noble gases

d)   Halogens 

Elements, Compounds, Mixtures Answers

I.               Classify the following as element (E), compound (C), homogeneous mixture (Hom), or heterogeneous mixture (Het).

a)    Water and sugar before dissolving ____Het___

b)   Water and salt after dissolving __Hom_____

c)    Milk ___Hot____

d)   Potassium __E_____

e)    Distilled water __C_____

f)     Helium ___E____

g)    Pepperoni pizza __Het_____

h)   Water and oil ___Het____

i)     Sodium ___E____

j)     Cholesterol __C_____

k)    Table salt ___C____

l)     NaCl ___C____

m)  HCl _(g) __C_____

n)   HCl _(aq) ___Hom____

o)    Air __Hom_____

p)   Blood ___Hom____

Measurements, Calculations and Conversions Answers

1                II.   How many significant figures?

a)    0.003250 _______4_________

b)   2001.5 _________5__________

c)    001.0 ____________2_______

d)   6.022 X 10²³ ______4_______

e)    2 ________Infinite__________

f)     2.0 _________2____________

III. Perform the following calculation and round to the correct number of 
significant digits:

a) (22.23 + 14.2) / (17.6 - 8.311)

b) (9.4 X 10²² + 18.44 X 10²¹) x 44.4 x 10^-18

IV. Decimal to scientific notation and scientific to decimal notation

 a)    2,853,450,000 = 2.85345×10⁹

             b) 0.000000052 = 5.2×10⁻⁸

             c) 2,853,450,001 = 2.85345001×10⁹

             d) 3.557 X 10² = 355.7

             e) 2.438 X 10^-5 = 0.00002438

  V. Which of the following is correct

                  a) 1kg = 1000 g
                  b) 1kg = 1x10³ g
                  c) Both a and b are correct 

VI.  

VII. The area of a golf course is measured to be 3.5 square miles. Calculate the area of
the golf course in square meters using the following conversion factors:
(1 mi = 5280 ft; 1 ft = 12 in; 1 in = 2.54 cm; 1 m = 100 cm).

  VIII. Convert the following

  a)    47.8 L = 47800 mL

  b)   16 L = 16000 mL

  c)    32780 mL = 32.78 L

  d)   5000 mL = 5 L

IX. Calculate BMI for

  a) 70 kg; 1.80 m = 21.6
  b) 75 kg; 6.2 ft = 21
  c) 180 lb; 160 cm = 31. 6
  d) 130 lb; 5.9 ft = 18.4
  e) 100 kg; 5.3 ft = 38. 6

Organic and Inorganic Chemistry Answers

1  I. Classify the following compounds as Organic (O) or Inorganic (I)

a)    Cholesterol _____O____

b)   CO2 _________I________

c)    CaCO₃ _____I__________

d)   H2O_________I_________

e)    C6H12O6____O________

f)     Glucose_____O_________

g)    NaHCO3_____I________

h)   Hemoglobin__O_______

i)     HCl _________I_________

j)     Carbon monoxide ____I_________

k)    NaOH ______________I_____________

l)     H2SO4_______________I____________

m)  Vitamin D ____________O___________

n)   Calcium ___________I______________