AP Chemistry Midterm Review

A 15.67 g sample of a hydrate of magnesium carbonate was heated to drive off the water. The mass was reduced to 7.58 g. What is the formula of the hydrate?

• MgCO₃ · 5H₂O
• MgCO₃ · 4H₂O
• MgCO₃ · 6H₂O
• MgCO₃ · 1H₂O

Tags

NGSS.HS-PS1-7

NGSS.HS-PS1-2

Balance the reaction: _AlBr₃ + _K₂SO₄ → _KBr + _Al₂(SO₄)₃

• 6 AlBr₃ + 1 K₂SO₄ → 6 KBr + 1 Al₂(SO₄)₃

• 2 AlBr₃ + 3 K₂SO₄ → 6 KBr + 1 Al₂(SO₄)₃

• 1 AlBr₃ + 1 K₂SO₄ → 2 KBr + 3 Al₂(SO₄)₃

• 2 AlBr₃ + 3 K₂SO₄ → 1 KBr + 2 Al₂(SO₄)₃

Tags

NGSS.HS-PS1-7

Which is the correct net ionic equation for the reaction of aqueous AgNO₃ and aqueous CaCl₂?

• Ca²⁺(aq) +  2Cl^- (aq) → CaCl(s)

• Ag⁺(aq)  +  Cl^- (aq) → AgCl(s)

• Ag +  Cl  →  AgCl

• Ag⁺  +  Ca²⁺   →Ag₂Ca (s)

Tags

NGSS.HS-PS1-7

Which of the following choices ranks the molecules above in order of greatest to least polarity?

• B>D>C>A

• D>B>C>A

• B>C>D>A

• C>B>D>A

Which of the following choices correctly ranks the bond angles of the molecules from largest to smallest?

• SCl₂ > PCl₃ > CCl₄

• PCl₃ > CCl₄ > SCl₂

• PCl₃ > SCl₂ > CCl₄

• CCl₄ > PCl₃ > SCl₂

According to the VSPER model, the difference in bond angles between SCl₂, PCl₃, and CCl₄ is best explained by the

• difference in bond polarity between the central atom and chlorine

• number of unbonded electrons around the central atom

• size of the central atom

• difference in bond strength

Which of the following statements accurately describes the change that occurs in the forces of attraction between CO₂ molecules as they change phase from a gas to a solid?

• Covalent bonds between CO₂ molecules are formed, creating a network solid.

• Weak, permanent dipoles are formed by dispersion forces.

• The nuceli of the carbon and oxygen atoms in the CO₂ molecules form a crystalline structure within a sea of mobile electrons.

• Transient dipoles form between the molecules and become more powerful than the vibrations that tend to increase the distance between molecules.

Tags

NGSS.HS-PS1-3

Which of the following most directly explains the difference in melting points between BeO (2507°C) and NaCl (801°C)?

• NaCl is an ionic compound and BeO is a covalent (molecule)

• There is less distance between the sodium and chloride ions in NaCl compared to the distance between Beryllium and oxygen ions in BeO

• The sodium ion is larger and less positively charged than the beryllium ion; the chloride ion is larger and less negatively charged than the oxygen ion.

• Beryllium and oxygen have lower atomic numbers than sodium and oxygen, respectively.

Tags

NGSS.HS-PS2-4

Which of the following bonds has the greatest polarity?

• H-N

• H-O

• H-F

• F-I

Which of the following is expected to have the highest boiling point?

• Br₂

• Cl₂

• N₂

• O₂

Tags

NGSS.HS-PS1-3