AP Unit 4: Chemical Reactions

Which of the following reactions could be modeled using the following representation?

• AgCl --> Ag⁺ + Cl^-

• AgNO₃ + NaCl --> AgCl + NaNO₃

• AgCl + K --> Ag + KCl

• Ag⁺ + e^- --> Ag

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Which of the following statements BEST describes the difference between the two equations shown below?

Equation 1: H₂O _(l) --> H₂O_(g)

Equation 2: 2H₂O _(l) --> 2H_2(g) + O_2(g)

• Equation 1 represents a physical change because intermolecular forces are broken during the process, whereas Equation 2 represents a chemical change because intramolecular forces are broken

• Equation 1 represents a physical change because intramolecular forces are broken during the process, whereas Equation 2 represents a chemical change because intermolecular forces are broken

• Equation 1 represents a chemical change because intermolecular forces are broken during the process, whereas Equation 2 represents a physical change because intramolecular forces are broken

• Equation 1 represents a chemical change because intramolecular forces are broken during the process, whereas Equation 2 represents a physical change because intermolecular forces are broken

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

You mixed two aqueous solutions together, expecting to see a precipitate form. Instead, after several minutes, you do not SEE any changes.

Which of the following are other observations that could be recorded?

• gas bubbling

• heat evolving

• color change

• there are no other changes to look for because no reaction has occurred

Use the diagram below to help you.

Which of the following BEST describes what happens to C₂H₄ when a 5.00 g sample of C₄H₆ is mixed with a 10.00 g sample of C₆H₆ at -10.0°C?

• A chemical change occurs, and the C₄H₆ forms nonpolar covalent bonds with the C₆H₆

• A physical change occurs, and the C₄H₆ forms a thin, liquid layer above the liquid C₆H₆

• A chemical change occurs, as the C₄H₆ bonds are broken, and the individual C and H atoms are added to the C₆H₆ molecule to form C₁₀H₁₂

• A physical change occurs as the C₄H₆ forms London dispersion forces with the C₆H₆ to create a mixture.

Solutions of sodium carbonate and hydrochloric acid are mixed. Which of the following represents the balanced, net ionic reaction for this mixture?

• Na₂CO_{3 (aq)} + 2HCl _(aq) --> 2NaCl_(aq) + H₂CO_3(aq)

• CO₃^2-_(aq) + 2H⁺_(aq) --> H₂CO_3(aq)

• CO₃^2-_(aq) + 2H⁺_(aq) --> H₂O_(l) + CO_2(g)

• 2Na⁺ _(aq) + CO₃^2-_(aq) + 2H⁺_(aq) + 2Cl^-_(aq) --> 2Na⁺ _(aq) + 2Cl^-_(aq) + H₂O_(l) + CO_2(g)

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Reactions occurring in aqueous solution can be represented by three types of reaction equations: (1) a molecular equation, (2) a complete ionic equation, and (3) a net ionic equation. Sometimes, two of more of these wind up looking exactly the same.

Consider the reaction below:

Mg(OH)_2(aq) + H₂SO_4(aq)--> MgSO_4(s) + 2H₂O_(l)

Which of the following statements is TRUE concerning the molecular equation (shown above), the complete ionic equation and the net ionic equation for this reaction?

• All three equation types are the same

• All three equation types are different

• The molecular and complete ionic equations are the same, but the net ionic equation is different.

• The molecular equation is different from the other two, but the complete ionic and net ionic equations are the same.

Consider the decomposition reaction represented in the picture. Which of the following reaction equations would fit this decomposition?

• KClO₃ --> KCl + 3O₂

• Mg(ClO₃)₂ --> MgCl₂ + 3O₂

• Mg(ClO₃)₂ --> MgO₂ + 3Cl₂

• Pb(CO₃)₂ --> PbO₂ + 3CO₂

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-7

Consider the reaction:

2ZnS + 3O₂ --> 2ZnO + 2SO₂

This reaction has an 80.0% yield.

What mass of ZnO is produced when 50.0 g of ZnS is heated in an open vessel until no further weight loss is observed?

• 33.4 g

• 40.4 g

• 43.4 g

• 3240 g

Tags

NGSS.HS-PS1-7

Calcium reacts with water according to the following reaction:

Ca + 2H₂O --> Ca(OH)₂ + H₂

What volume of hydrogen gas, at 2.00 atm and 0.00°C, is produced from 20.0 g calcium and 20.0 g water?

• 0.559 L

• 5.46 L

• 109 L

• 219 L

For a titration using 12.00 mL of 0.50 M HCl and NaOH, which of the following is TRUE about the equivalence point?

• 1.5 mL of 2.0 M NaOH has been added

• 24.00 mL of 1.0 M NaOH has been added

• 12.00 mL of 1.0 M NaOH has been added

• 6.00 mL of 1.0 M NaOH has been added

Tags

NGSS.HS-PS1-7