AP Chemistry

When a sample of an unknown element is vaporized and injected into a mass spectrometer, the results shown below are obtained. Use these data to estimate the average atomic mass of this element.

• 117 amu

• between 117 and 118 amu

• between 118 and 119 amu

• between 119 and 120 amu

Tags

NGSS.MS-PS1-1

A clean strip of copper metal is massed and attached to a metal hook, suspended from a rubber stopper. The rubber stopper is placed into a very large test tube containing solid iodine, and the test tube is sealed. Iodine vapor is generated by gentle heating of the solid iodine at the bottom of the test tube. A white compound forms on the copper strip. The rubber stopper is carefully removed, and the resulting copper strip with the white compound is massed. The white compound is washed from the surface of the metal, and the copper strip is dried completely and massed. The data table is below. What is the empirical formula for this compound?

• CuI

• CuI₂

• Cu₂I

• Cu₃I₄

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

• 5.03 g

• 4.41 g

• .614 g

• 10.1 g

Tags

NGSS.HS-PS1-7

Determine the volume of distilled water that should be added to 20.0 mL of 12.0M HCl(aq) in order to prepare a 0.500 M HCl (aq) solution.

• 120. mL

• 140. mL

• 460. mL

• 480. mL

A scientist conducts an experiment to characterize a bomb containing nitroglycerine. She uses a steel, rigid container for the test. What is the total pressure produced in this explosion?

(Hint: PV=nRT)

• 25.0 atm

• 52.0 atm

• 179 atm

• 435 atm

Which of the following is true concerning real gases?

• The observed pressure will be less than the ideal pressure, and the volume available for the gas particles is less than the volume of the container.

• The observed pressure will be less than the ideal pressure, and the volume available for the gas particles is greater than the volume of the container.

• The observed pressure will be greater than the ideal pressure, and the volume available for the gas particles is greater than the volume of the container.

• The observed pressure will be greater than the ideal pressure, and the volume available for the gas particles is less than the volume of the container.

Choose the answers that are true to the Kinetic Molecular Theory.

• The Kinetic Molecular Theory is a simple model that attempts to explain the properties of an ideal gas.

• The particles of gas are so small compared with the distances between them that the volume of the individual particles can be assumed to be negligible.

• The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas.

• The particles are assumed to exert forces on each other.

• The particles of a gas are in constant motion.

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

Which of the following is the reason that ionization energy generally increases from left to right across the first period of the periodic table?

• As the atomic number increases, the electrons are harder to remove.

• Ionization energy increases as the atomic number increases in a period.

• As the atomic number increases, more electrons are added to the atoms, thus increasing the electron–electron repulsions.

• As the atomic number increases, more protons in the nucleus cause an increase in the effective nuclear charge, making it harder to remove the electrons.

Tags

NGSS.HS-PS1-2

Which of the following electron arrangements shows a violation of the orbital notation of electron configurations?

(Hint: Hund's Rule)

• 
• 
• 
• 

Tags

NGSS.HS-PS1-1

Once the system reaches equilibrium at 675C, additional H₂ is added and the temperature is held constant. Which statement best describes how this affects the value of K ?

• The value of K increases because the formation of products is favored.

• The value of K decreases because the formation of reactants is favored.

• The value of K remains unchanged because the temperature remained constant.

• The value of K cannot be determined until the equilibrium concentrations are determined.

Tags

NGSS.HS-PS1-5