Module 5-6

Precipitation Reactions

100

Characterize the following compounds as soluble or insoluble in water:
1.Ca₃(PO₄)₂

2.Mn(OH)₂

3.AgClO₃

4.K₂S

1. Insoluble

2. Insoluble

3. Soluble

4. Soluble

200

Characterize the following compounds as soluble or insoluble in water:

1. CaCO₃

2. ZnSO₄

3. Hg(NO₃)₂

4. HgSO₄

5. NH₄ClO₄

1. Insoluble

2. Soluble

3. Soluble

4. Insoluble

5. Soluble

300

Write ionic & net ionic equations for the following reaction:

K₃PO_4(aq)+ 3Sr(NO₃)_{2(aq) ---->}

K₃PO_4(aq)+ 3Sr(NO₃)_{2(aq) ---->}

Ionic: 6K⁺+2PO₄^-3+3Sr⁺²+6NO₃---> Sr₃(PO₄)_2(s)+6K⁺+6NO₃

Net Ionic: 3Sr⁺²_(aq)+2PO₄^-3_(aq)---->Sr₃(PO₄)_2(s)

400

What are the spectator ions in the following reaction:

Na₂S_(aq)+ZnCl_2(aq)--->

2Na⁺ and  2Cl^-

500

Which of the following processes will likely result in a precipitation reaction? What will be the precipitate?

Mixing NaNO₃ solution with a CuSO₄ solution

Mixing BaCl₂ solution with a K₂SO₄ solution

Mixing BaCl₂ solution with a K₂SO₄ solution

Precipitate is BaSO₄

Molarity

100

How many grams of KOH are present in 35.0 mL of 5.50 M solution?

10.8 g of KOH

200

How many moles of NaNO₃ are needed to prepare 250 mLof a 0.707M MgCl₂ solution?

0.177 moles of NaNO₃

300

What is the molarity of an 85.0 mL ethanol solution containing 1.77 g of ethanol (C₂H₅OH)?

0.452 M C₂H₅OH

400

What volume in mL of a 0.315 M NaOH solution contains 6.22 g of NaOH?

494 mL 

500

A chemist needs to add 3.81 g of glucose to a reaction mixture. Calculate the volume in mL of a 2.53 M glucose solution she should use for the addition.

8.36 mL

Acid-Base Reactions/Titrations

100

Identify each of the following species as a Bronsted acid, base, or both:

PO₄^-3, ClO2^-, NH₄⁺, HCO₃^-

Base, Base, Acid, Both

200

Complete the following equation:

CH₃COOH+KOH--->

CH₃COOH+KOH--->KCH₃COO+H₂O

300

Calculate the concentration, in molarity, of a NaOH solution if 25.0 mL of the solution are needed to neutralize 17.4 mL of a 0.312 M HCl solution.

0.217 M NaOH

400

How many milliliters of a 0.610 M NaOH solution are needed to neutralize 20.0 mL of a 0.245 M H₂SO₄ solution?

16.1 mL of NaOH

500

Define equivalence point

The point at which the acid has completely reacted with or been neutralized by the base.

Oxidation Numbers

100

What is the oxidation number of Cr in Cr₂O₇^2-?

+6

200

Assign oxidation numbers to all the elements in the following compound:

PF₃

P:-3

F:-1

300

What is the oxidation number for Mn in KMnO₄?

+7

400

Give the oxidation numbers of:
C in CaC₂

O in ZnO₂^-2

W in WO₄^-2

C:-1

O:-2

W:+6

500

Arrange the following species in order of increasing oxidation number of the sulfur atom:

H₂S, S₈, H₂SO₄, HS^-

H₂S,HS^-, S₈, H₂SO₄

Redox Reactions

100

Which element is oxidized and which is reduced?

2 Sr+O₂---> 2 SrO

Oxidized: Strontium

Reduced: Oxygen

200

Which element is the oxidizing agent and reducing agent?

2 Li + H₂ ---> 2 LiH

Oxidizing agent: H₂

Reducing agent: Li

300

Classify the following redox reaction:

Cl₂+ 2KI---> 2KCl + I₂

Single displacement reaction

400

Write the half reaction for the following redox reaction:

4Fe+3O₂---> 2Fe₂O₃

Fe---> Fe³⁺ + 3e^-

O₂+4e^----> 2O^2-

500

Write the half-reactions and identify the oxidizing and reducing agents:

H₂+Cl₂--->2HCl

Oxidizing agent: Cl₂

Reducing agent: H₂

H₂---> 2H + 2e-

Cl₂+2e^---->2Cl^-