Chemistry Concepts and Calculations

What is the correct name for the compound N2O5?

• Dinitrogen pentoxide

• Nitrogen pentoxide

• Dinitrogen oxide

• Nitrogen dioxide

How many grams of ammonia are produced when 15 grams of nitrogen gas react with excess hydrogen gas?

• 10.5 grams

• 15.0 grams

• 18.24 grams

• 20.0 grams

What is the oxidation state of chromium in sodium dichromate?

• +4

• +2

• +6

• +3

Calculate the density of oxygen gas at STP.

• 0.89 g/L

• 2.00 g/L

• 1.43 g/L

• 1.00 g/L

Which gas constant should be used when pressure is measured in atmospheres?

• 8.3145 J/(mol·K)

• 62.36 L·mmHg/(mol·K)

• 0.08206 L·atm/(mol·K)

• 1.987 cal/(mol·K)

What is the phase change called when a gas turns directly into a solid?

• Sublimation

• Freezing

• Condensation

• Deposition

How many orbitals are present in the n=4 principal energy level?

• 8

• 16

• 64

• 32

Which of the following has the shortest wavelength in the electromagnetic spectrum?

• Gamma rays

• Microwaves

• Infrared

• Radio waves

What is the molecular geometry of BF3?

• Trigonal planar

• Tetrahedral

• Bent

• Linear

Which intermolecular force is the strongest?

• Van der Waals forces

• Hydrogen bonds

• Dipole-dipole interactions

• London dispersion forces