AP midterm

Unit 1

100

What orbital does a PES graph always start with 

1s¹

200

Which of the following elements or ions is the smallest Cl or Cl-1?

 Cl

300

What are the empirical formula and the molecular formula for resorcinol? It is 65.44% carbon, 5.49% hydrogen, and 29.06% oxygen.

C₃H₃O₁

Unit 1

100

How do you become a cation?

lose electrons

200

 What type of ion is Cl-1?

anion

300

Caffeine contains 49.5% C, 5.15% H, 28.9% N and 16.5 % O. What are its empirical and molecular formulas?

C₄H₅N₂O₁

Unit 2

100

On the basis of electronegativity differences between atoms, which of the following scientific claims is the most accurate regarding the bonding in Mg(NO3)2(s)?

There is ionic bonding between Mg2+ ions and NO3− ions.

200

Imagine 2 identical +1.0 C charges are placed 1.0 m apart from each other. What would be the strength of the Electrostatic force between these charges?

9E9

300

Two sealed, rigid 5.0L containers each contain a gas at the same temperature but at a different pressure. Which statement is correct regarding the total pressure of the gases after they are combined?

The total pressure of the gases in the mixture is the sum of the initial pressures of oxygen gas and nitrogen gas because pressure only depends on the total amount of gas when volume and temperature are held constant

Unit 2

100

Which of the following claims about a binary compound in which the bonding is ionic is most likely to be scientifically valid?

1. Both elements in the compound are metals.

2. There is equal sharing of electrons between the atoms of the elements in the compound.

3. The electronegativity difference between the elements in the compound is relatively large.

3. The electronegativity difference between the elements in the compound is relatively large.

200

If N2 is two of the same atom is it polar or nonpolar?

nonpolar

300

A 500.mL aqueous solution of Na3PO4 (molar mass=164g/mol) was prepared using 82g of the solute. What is the molarity of Na3PO4 in the resulting solution?

1.0M

Unit 3

100

Which of the following methods is most appropriate to use to determine the number of different-colored components in a sample of black ink?

Paper chromatography using different solvents with a range of polarities as the mobile phase

200

Which statement correctly compares crystalline NaBr(s) to molten NaBr(l) in terms of electrical conductivity?

a. Crystalline NaBr and molten NaBr both contain Na atoms that transfer electrons to Br atoms in a chemical reaction, thus allowing them both to be good conductors of electricity.

b.Crystalline NaBr contains no freely moving electrons to conduct electricity, but molten NaBr is composed of freely moving Na+ and Br− ions, which allows it to be a good conductor of electricity.

b.Crystalline NaBr contains no freely moving electrons to conduct electricity, but molten NaBr is composed of freely moving Na+ and Br− ions, which allows it to be a good conductor of electricity.

300

A gaseous air‑fuel mixture in a sealed car engine cylinder has an initial volume of 600.mL at 1.0atm. To prepare for ignition of the fuel, a piston moves within the cylinder, reducing the volume of the air‑fuel mixture to 50.mL at constant temperature. Assuming ideal behavior, what is the new pressure of the air‑fuel mixture?

About 12atm, because the volume of the gas mixture decreased by a factor of 12.