AP Chemistry Unit 4

Physical vs Chemical changes and types of Chemical reactions

100

Is burning wood a physical or chemical reaction?

Chemical

200

Is changing states of matter a physical or chemical change?

Physical 

300

What is the general form for a double replacement reaction?

AB + CD --> AD + CB

400

What reactants do you need to form products of some type of salt and water?

Acid and Base

500

What specific type of double replacement reaction would form AgCl_(s) from NaCl_(aq) and AgNO3_(aq)?

Precipitation reaction

Net Ionic Equations

100

What is eliminated from a net ionic equation?

Any substance that does not change from the left to the right side (spectator ions). 

200

What spectator ions can be found in the following equation: AgNO_3(aq) + NaCl_(aq) --> AgCl_(s) + NaNO_3(aq). 

Na⁺ and NO₃^-

300

What is the net ionic equation if the complete ionic equation is Ag⁺_(aq) + NO₃⁻_(aq) + K⁺_(aq) + Cl^- _(aq) --> AgCl_(s) + K⁺_(aq) + NO3^-_(aq)

Ag⁺_(aq) Cl^-_(aq) --> AgCl_(s) 

400

What is the net ionic equation for combining HCl_(aq) and NaOH_(aq)?

H⁺_(aq) + OH^-_(aq) → H2O_(l)

500

Write and balance the molecular and net ionic equation for combining aqueous barium nitrate and aqueous ammonium phosphate?

Molecular: 3 Ba(NO₃)_2(aq) + 2 (NH₄)₃PO_4(aq) --> Ba₃(PO₄)_2(s) + 6 NH₄NO_3(aq)

Net: 3 Ba ²⁺_(aq) + 2 PO₄^3-_(aq) --> Ba₃(PO₄)_2(s) 

Redox Reactions

100

Is oxidation the loss or gain of electrons?

Loss of electrons

200

What is the oxidation number of H_2(g)?

0 

300

What is special about Hydrogen's oxidation number?

Hydrogen's oxidation number can behave as a metal and nonmetal. When bonded to a metal its oxidation number is -1 and when bonded to a nonmetal its oxidation number is +1.

400

In the equation: Mg_(s) + 2 HCl_(aq) --> MgCl_2(aq) + H_2(g) what are the original and final oxidation numbers of Magnesium and was it oxidized or reduced?

Starting oxidation #: 0 

Final oxidation #: +2

Oxidized 

500

In the following equation identify which substances are the oxidizing and reducing agents as well as which substances are oxidized and reduced. 

Fe₂O_3(s) + 2 Al_(s) --> Al₂O_3(s) + 2 Fe_(l)

Oxidizing Agent : Fe₂O₃

Reducing Agent : Al

Substance oxidized : Al 

Substance reduced: Fe

Acids and Bases

100

What is the definition of Arrhenius acids and bases?  

Arrhenius- when dissolved in water Acids increase H⁺_(aq) concentration and bases increase the OH^-_(aq) concentration. 

200

What is the difference between Brønsted-Lowry acids and Brønsted-Lowry bases?

Brønsted-Lowry acids are proton(H⁺) donors and their bases are proton(H⁺) acceptors.

300

Explain the difference between conjugate Acids and conjugate Bases.

A Conjugate Base is the product after an acid has donated a proton. A Conjugate Acid is the particle produced when a base accepts a proton. 

400

In the following equation identify the Acids and bases along with their conjugate Acids and bases.

NH_3(aq) + HCl_(aq) --> NH₄⁺_(aq) + Cl^-_(aq)

Acid: HCl

Base: NH₃

CA: NH₄⁺

CB: Cl^-

500

List the Acids and bases and their conjugates for a reaction combining a hydrogensulfate ion and a cyanide ion.

Acid: HSO₄^-

Base:  CN^-

CA: HCN

CB: SO₄^2-

Solubility

100

What would HClO₄ look like dissociated?

H⁺ and ClO₄^-

200

Is Mg(OH)₂ soluble or insoluble?

insoluble

300

Would acetic acid (CH₃COOH) dissociate 100% in a solution?

No, it does not dissociate 100% since acetic acid is a weak acid. Weak acids only partially ionize into ions. 

400

Is silver chloride soluble or insoluble? (If soluble write the ions) 

insoluble

500

Is ammonium sulfate soluble or insoluble? (If it is soluble write the ions it dissociates into)

soluble 

Ions: NH₄⁺ and SO₄^2-