G11_Diagnostic test

What amount of oxygen, O₂, (in moles) contains 1.8×10²² molecules?

• 0.0030

• 0.030

• 0.30

• 3.0

__C₂H_2(g) + __O_2(g) → __ CO_2(g) + __ H₂O_(g)

When the equation above is balanced, what is the coefficient for oxygen?

• 2

• 3

• 4

• 5

What will happen to the volume of a fixed mass of gas when its pressure and temperature

(in Kelvin) are both doubled?

• It will not change.

• It will increase.

• It will decrease.

• The change cannot be predicted.

Consider the composition of the species W, X, Y, and Z below. Which species is an anion?

• W

• X

• Y

• Z

Which is related to the number of electrons in the outer main energy level of the elements from the alkali metals to the halogens?

I. Group number

II. Period number

• I only

• II only

• Both I and II

• Neither I nor II

Which pair of elements reacts most readily?

• Li + Br₂

• Li + Cl₂

• K + Br₂

• K + Cl₂

What is the formula for the compound formed by calcium and nitrogen?

• CaN

• Ca₂N

• Ca₂N₃

• Ca₃N₂

Which of the following is true for CO₂?

• A

• B

• C

• D

The molar masses of C₂H₆, CH₃OH, and CH₃F are very similar. How do their boiling points compare?

• C₂H₆ < CH₃OH < CH₃F

• CH₃F < CH₃OH < C₂H₆

• CH₃OH < CH₃F < C₂H₆

• C₂H₆ < CH₃F < CH₃OH

What energy changes occur when chemical bonds are formed and broken?

• Energy is absorbed when bonds are formed and when they are broken.

• Energy is released when bonds are formed and when they are broken.

• Energy is absorbed when bonds are formed and released when they are broken.

• Energy is released when bonds are formed and absorbed when they are broken.