CHM 113 FINAL QUESTIONS &
ANSWERS 100% CORRECT
Which of the following statements is false regarding an element?
A. An element is only made up of one type of atom.
B. An element can be both a molecule AND a compound.
C. An element can be a molecule.
D. Atoms of an element cannot decompose into smaller substances with chemical
properties. - ANSWERFalse:
An element can be both a molecule AND a compound.
Match each chemical symbol with its name
C
Cl
Ca
Co - ANSWERC: Carbon
Cl: Chlorine
Ca: Calcium
Co: Cobalt
Classify the substances below as either as an element or a compound:
- air
- hydrogen gas
- ammonia
- iron metal
- granite
- sodium chloride - ANSWERElements:
- hydrogen gas
- iron metal
Compounds:
- air
- ammonia
- granite
- sodium chloride
Hydrogen sulfide(H2S) is composed of two elements: hydrogen and sulfur. In an
experiment, 6.500g of hydrogen sulfide is fully decomposed into its elements as
seen in the reaction below.
𝟐𝑯𝟐𝑺(𝒈) → 𝟐𝑯𝟐(𝒈) + 𝑺𝟐(𝒈)
• If 0.384g of hydrogen is obtained in this experiment, how many grams of sulfur
mustbe obtained? - ANSWER6.500 g - 0.384 g = 6.116
Which classification of matter best describes this sample? - ANSWERheterogenous
mixture
Identify the following as chemical or physical properties.
, • Aluminum is malleable (able to be hammered into a sheet)
• Ability of nitric acid to dissolve copper
• Density of mercury
• Boiling point of water
• Flammability of hydrogen (H2)
• Copper is ductile (able to be pulled into a wire) - ANSWER• Aluminum is malleable
(able to be hammered into a sheet)
--> physical property
• Ability of nitric acid to dissolve copper
--> chemical property
• Density of mercury
--> physical property
• Boiling point of water
--> physical property
• Flammability of hydrogen (H2)
--> chemical property
• Copper is ductile (able to be pulled into a wire)
--> physical property
Classify the following changes as chemical or physical
• Aluminum is hammered into a sheet
• Copper is oxidized by concentrated nitric acid
• Metabolism of ethanol
• Dry ice sublimating at room temperature
• Dissolving sodium chloride in water
• Hydrogen gas burning in the presence of oxygen
• Liquid nitrogen boiling at room temperature
• Rust forming on an iron pipe - ANSWER• Aluminum is hammered into a sheet
--> physical
• Copper is oxidized by concentrated nitric acid
--> chemical
• Metabolism of ethanol
--> chemical
• Dry ice sublimating at room temperature
--> physical
• Dissolving sodium chloride in water
--> physical change
• Hydrogen gas burning in the presence of oxygen
--> chemical change
ANSWERS 100% CORRECT
Which of the following statements is false regarding an element?
A. An element is only made up of one type of atom.
B. An element can be both a molecule AND a compound.
C. An element can be a molecule.
D. Atoms of an element cannot decompose into smaller substances with chemical
properties. - ANSWERFalse:
An element can be both a molecule AND a compound.
Match each chemical symbol with its name
C
Cl
Ca
Co - ANSWERC: Carbon
Cl: Chlorine
Ca: Calcium
Co: Cobalt
Classify the substances below as either as an element or a compound:
- air
- hydrogen gas
- ammonia
- iron metal
- granite
- sodium chloride - ANSWERElements:
- hydrogen gas
- iron metal
Compounds:
- air
- ammonia
- granite
- sodium chloride
Hydrogen sulfide(H2S) is composed of two elements: hydrogen and sulfur. In an
experiment, 6.500g of hydrogen sulfide is fully decomposed into its elements as
seen in the reaction below.
𝟐𝑯𝟐𝑺(𝒈) → 𝟐𝑯𝟐(𝒈) + 𝑺𝟐(𝒈)
• If 0.384g of hydrogen is obtained in this experiment, how many grams of sulfur
mustbe obtained? - ANSWER6.500 g - 0.384 g = 6.116
Which classification of matter best describes this sample? - ANSWERheterogenous
mixture
Identify the following as chemical or physical properties.
, • Aluminum is malleable (able to be hammered into a sheet)
• Ability of nitric acid to dissolve copper
• Density of mercury
• Boiling point of water
• Flammability of hydrogen (H2)
• Copper is ductile (able to be pulled into a wire) - ANSWER• Aluminum is malleable
(able to be hammered into a sheet)
--> physical property
• Ability of nitric acid to dissolve copper
--> chemical property
• Density of mercury
--> physical property
• Boiling point of water
--> physical property
• Flammability of hydrogen (H2)
--> chemical property
• Copper is ductile (able to be pulled into a wire)
--> physical property
Classify the following changes as chemical or physical
• Aluminum is hammered into a sheet
• Copper is oxidized by concentrated nitric acid
• Metabolism of ethanol
• Dry ice sublimating at room temperature
• Dissolving sodium chloride in water
• Hydrogen gas burning in the presence of oxygen
• Liquid nitrogen boiling at room temperature
• Rust forming on an iron pipe - ANSWER• Aluminum is hammered into a sheet
--> physical
• Copper is oxidized by concentrated nitric acid
--> chemical
• Metabolism of ethanol
--> chemical
• Dry ice sublimating at room temperature
--> physical
• Dissolving sodium chloride in water
--> physical change
• Hydrogen gas burning in the presence of oxygen
--> chemical change
