PORTAGE LEARNING CHEM 121 MODULE 1 EXAM
QUESTIONS AND ANSWERS 2026/2027 | GRADED A+
| NEW UPDATE!!!
1. Convert 1005.3 to exponential form and explain your answer.
2. Convert 4.87 x 10-6 to ordinary form and explain your answer. -
ANSWER-- Convert 1005.3 = larger than 1 = positive exponent, move decimal 3
places =
1.0053 x 103
2. Convert 4.87 x 10-6 =negative exponent =smaller than 1, move decimal 6 places
= 0.00000487
1. 350 pounds = ? ton
2. 0.632 m = ? cm - ANSWER--1. 350 pounds x 1 ton / 2000 pounds = 0.175 ton
2. 0.632 m x 100 cm / 1 m = 63.2 cm
1. 246 oK = ? oC
2. 45 oC = ? oF
3. 18 oF = ? oK - ANSWER--1. 246oK - 273 = -27 oC oK → oC (make smaller) -273
,2. 45oC x 1.8 + 32 = 113 oF oC → oF (make larger) x 1.8 +
32
3. 18oF - 32 ÷ 1.8 = -7.8 + 273 =
265.2 oK oF → oC → oK
1. Show the calculation of the mass of a 18.6 ml sample of freon with density
of 1.49 g/ml
Classify each of the following as a chemical change or a physical change
1. Charcoal burns
2. Mixing cake batter with water
3. Baking the batter to a cake - ANSWER--1. Charcoal burns - burning always =
chemical change
2. Mixing cake batter with water - mixing = physical change
3. Baking the batter to a cake - baking converts batter to new material = chemical
change
, Show the full Nuclear symbol including any + or - charge (n), the atomic number
(y), the mass number (x) and the correct element symbol (Z) for each element for
which the protons, neutrons and electrons are shown - symbol should appear as
follows: xZy+/- n
31 protons, 39 neutrons, 28 electrons - ANSWER--31 protons = Ga31, 39 neutrons
= 70Ga31, 28 electrons = (+31 - 28 = +3) = 70Ga31+3
Name each of the following chemical compounds. Be sure to name all acids as
acids (NOT for instance as binary compounds)
1. PF5
2. Al2(CO3)3
3. H2CrO4 - ANSWER--1. PF5 - binary molecular = phosphorus pentafluoride
2. Al2(CO3)3 - nonbinary ionic = aluminum carbonate
3. H2CrO4 - nonbinary acid = chromic acid
Classify each of the following as an element, compound, solution or
heterogeneous mixture and explain your answer.
1. Pepperoni Pizza
2. Potassium oxide
3. Phosphorus - ANSWER--1. Pepperoni Pizza - is not on periodic table (not
element) - no element names (not compound)
QUESTIONS AND ANSWERS 2026/2027 | GRADED A+
| NEW UPDATE!!!
1. Convert 1005.3 to exponential form and explain your answer.
2. Convert 4.87 x 10-6 to ordinary form and explain your answer. -
ANSWER-- Convert 1005.3 = larger than 1 = positive exponent, move decimal 3
places =
1.0053 x 103
2. Convert 4.87 x 10-6 =negative exponent =smaller than 1, move decimal 6 places
= 0.00000487
1. 350 pounds = ? ton
2. 0.632 m = ? cm - ANSWER--1. 350 pounds x 1 ton / 2000 pounds = 0.175 ton
2. 0.632 m x 100 cm / 1 m = 63.2 cm
1. 246 oK = ? oC
2. 45 oC = ? oF
3. 18 oF = ? oK - ANSWER--1. 246oK - 273 = -27 oC oK → oC (make smaller) -273
,2. 45oC x 1.8 + 32 = 113 oF oC → oF (make larger) x 1.8 +
32
3. 18oF - 32 ÷ 1.8 = -7.8 + 273 =
265.2 oK oF → oC → oK
1. Show the calculation of the mass of a 18.6 ml sample of freon with density
of 1.49 g/ml
Classify each of the following as a chemical change or a physical change
1. Charcoal burns
2. Mixing cake batter with water
3. Baking the batter to a cake - ANSWER--1. Charcoal burns - burning always =
chemical change
2. Mixing cake batter with water - mixing = physical change
3. Baking the batter to a cake - baking converts batter to new material = chemical
change
, Show the full Nuclear symbol including any + or - charge (n), the atomic number
(y), the mass number (x) and the correct element symbol (Z) for each element for
which the protons, neutrons and electrons are shown - symbol should appear as
follows: xZy+/- n
31 protons, 39 neutrons, 28 electrons - ANSWER--31 protons = Ga31, 39 neutrons
= 70Ga31, 28 electrons = (+31 - 28 = +3) = 70Ga31+3
Name each of the following chemical compounds. Be sure to name all acids as
acids (NOT for instance as binary compounds)
1. PF5
2. Al2(CO3)3
3. H2CrO4 - ANSWER--1. PF5 - binary molecular = phosphorus pentafluoride
2. Al2(CO3)3 - nonbinary ionic = aluminum carbonate
3. H2CrO4 - nonbinary acid = chromic acid
Classify each of the following as an element, compound, solution or
heterogeneous mixture and explain your answer.
1. Pepperoni Pizza
2. Potassium oxide
3. Phosphorus - ANSWER--1. Pepperoni Pizza - is not on periodic table (not
element) - no element names (not compound)
