Pretest-Chemistry

Which of these would be best to measure 12.6 mL of liquid ethanol?

• 25 mL beaker

• 25 mL volumetric flask

• 25 mL Erlenmeyer flask

• 25 mL graduated cylinder

Potassium (K) has a smaller atomic mass than argon (Ar) even though the atomic number of potassium is larger than the atomic number of argon. Which of the following best accounts for this observation?

• At STP, potassium is in the solid phase, but argon is a gas.

• It is easier for a potassium atom to lose an electron than it is for an argon atom.

• The most common isotopes of argon have more protons than the most common isotopes of potassium.

• The most common isotopes of potassium have fewer neutrons than the most common isotopes of argon.

Which of the following is the correct Lewis electron-dot diagram for the sodium atom?

• 
• 
• 
• 

Tags

NGSS.HS-PS1-1

A compound has a mass of 2.6632 × 10² g/mol. The number of significant figures in this mass is —

• 2

• 4

• 5

• 7

What are the coefficients of the correctly balanced equation?

• 1, 3, 2, 3

• 0, 2, 2, 3

• 1, 2, 2, 2

• 2, 6, 4, 3

Tags

NGSS.HS-PS1-7

The correct formula for dinitrogen pentoxide is

• N₂O₅

• N₅O

• NO₅

• N₂O

When ionic compounds are named, the name of a monatomic anion will end in which of the following suffixes?

• -ic

• -ite

• -ate

• -ide

When 1 g of sodium chloride (NaCl) is placed in 100 g of water, a solution results. Once the solution is prepared, water is now considered what part of the solution?

• Solute

• Solid

• Solvent

• Liquid

What is the name of the compound with the formula PCl₅?

• Phosphorus(I) chloride

• Phosphorus(V) chlorine

• Phosphorus pentachlorate

• Phosphorus pentachloride

How many electrons does the iron ion have when it forms the ionic compound FeCl₃ ?

• 20

• 23

• 26

• 29