Chapter 17 Chemical Change: Test A

In which of the following situations does water undergo a change in physical properties?

• The bathroom fills with steam when you take a hot shower.

• The neighbor's pond freezes over in winter.

• Water is broken down to yield H₂ and O₂.

Identify the reactants in the combustion of methane.

• CO₂ and H₂O

• CH₄ and O₂

• O₂ and H₂O

• CH₄ and CO₂

Identify the products in the combustion of methane.

• CO₂ and H₂O

• CH₄ and O₂

• O₂ and H₂O

• CH₄ and CO₂

Is the chemical reaction for the combustion of methane balanced? If not, select the correct equation from the ones listed below.

• Yes, it is balanced.

• No, this is balanced: CH₄ + O₂ → CO₂ + 4H₂O

• No, this is balanced: CH₄ + 2O₂ → CO₂ + 2H₂O

• No, this is balanced: CH₄ + 4O₂ → CO₂ + H₂O

The statement, “ the process of breaking chemical bonds and reforming new bonds to create new substances” can be used to describe:

• physical change only

• chemical change only.

• both physical and chemical change.

• neither physical nor chemical change.

Of the following, the one which most likely involves a chemical reaction is:

• Slicing a piece of bread produces two pieces.

• Placing a solid and a liquid together produces heat and a gas.

• Hitting a board with a hammer forms a dent in the surface of the wood.

• Heating an ice cube produces liquid water.

In the equation: Pb(NO)_3(aq) + 2KI_(aq) → PbI2_(s) + 2KNO_3(aq) in what form does PbI₂ appear?

• Solid

• Liquid

• Precipitate

• Both solid and precipitate.

In the reaction, 2H_2(g) + O_2(g) → 2H₂O_(l), the phase of matter in which the reactants appear is:

• solid

• liquid

• gas

• plasma

In the periodic table notation below, what information does the number 40.08 tell you?

• It is the number of protons.

• It is the number of neutrons.

• It is the atomic number.

• It is the atomic mass.

The Avogadro number is equal to:

• One mole of a substance.

• 6.02 × 10²³ molecules.

• the number of atoms in the atomic mass of an element, when the mass is expressed in grams.

• All of the above.