introduction welcome to the virtual lab simulation of a common qualitative analysis lab. the goal of...

IntroductionWelcome to the virtual lab simulation of a common

qualitative analysis lab. The goal of this lab will be toidentify several unknown chemicals based on their

reactive properties with other chemicals. In this first partof the lab you will observe what happens when you

mix a number of known chemicals together. You will then create a list of observations that will allow you to determine the identity of your unknown chemicals in the second portion

of the lab. Keep good notes on the color of the solutions thatare formed and also the precipitates that you observe. Keepin mind solubility rules and ion charges to create an accurate

picture of what is happening in each reaction.

Helpful Hints• If a precipitate forms, use the solubility rules to identify the

precipitate. You will be required to write out the total and net ionic equations for every precipitate that forms in both this and the next part of the lab.

• Remember that each of the chemicals that you are combining contain both a cation and an anion so you will end up with two new products. You must identify the complete compound (cation and anion) present in each unknown in the second part of the lab. Look at the animation below to understand what is happening when you react two compounds together. Using this general concept, you will be able to figure out what products are formed in each reaction.

++ - - Click here to show animation

Molecules involved

Pb2+

Ba2+Ag+Cu2+ Co2+

Fe3+Mg2+Na2+Li+

NO3- SO4

2- Cl- OH-

Every compound you will use will contain both an anion and a cation from those shown on this page. The solubility of each compound can be determined using the solubility rules on the next page. The colors of each ion will help you to identify them, the colors of the ions on this page correspond to the color of each ion in solution.

Solubility Rules

• Nitrates– Always Soluble

• Chlorides– Soluble; Exceptions: Ag+, Hg2

2+, Pb2+

• Hydroxides– Insoluble; Exceptions: Alkali Metals, Ba2+

• Sulfates– Soluble; Exceptions: Ba2+, Pb2+, Ag+

Below you will find solubility information for the chemicals that you will be using in this lab: Note: The solubility rules are far more complex and inclusive than what you are shown and can be found in your textbook on page 447.

Flame Tests

• One way in which we can identify the presence of a metal in a an unknown solution is by carrying out a flame test. – A loop made out of nichrome wire is used to collect a small

amount of the unknown. The wire is then inserted in a flame and the color of the flame is observed. The color of the flame can identify an element that is present. Click here to see a table of flame colors.

Click here to show animation

Barium Yellow-Green

Sodium Yellow

Copper Blue-Green

Lithium Red

Lead Pale Blue

Flame Test Color Reference

Problem Solving StrategyYou will need to develop an effective strategy to identify your unknowns. Answer

the following questions to demonstrate your understanding.

In the first part of the lab you should be able to predict whether a reaction between two products will produce a precipitate before you carry out the reaction. How will you know this?

a.) because I googled it

b.) because I looked at the solubility rules and determined the solubility of each of the new products formed

c.) because every combination of reactants in this experiment will result in a precipitate.

Correct:

The solubility rules will aid you in determining which reactions will form precipitates.

Click close to continue

X Close

Problem Solving Strategy You will need to develop an effective strategy to identify your unknowns. Answer


A compound containing OH- and any anion except _______ will produce a precipitate. Therefore, it will be easy to narrow down the identity of your unknown if it does not form a precipitate with a compound containing OH

a.)Li+ and Fe3+

b.)Li+ and Na+

c.) Ba2+, Ag+

Incorrect:

Fe3+ will form a precipitate

Click close to try again

X CloseIncorrect:

Ba2+ and Ag+ will form precipitates


X CloseCorrect:

Per the solubility rules, the only cations that will not form a precipitate with OH- are Li+ and Na+


X Close

Problem Solving Strategy You will need to develop an effective strategy to identify your unknowns. Answer


A flame test can be used to identify the presence of several different _______ by the color of the flame. Once you have done so, the solubility rules can be used to identify the _______.

a.) Cations, anion

b.) Anions, cation

c.) Solubility

Correct


X CloseIncorrect:

This answer is incorrect, a flame test tells us nothing about the solubility of an unknown directly.


X CloseIncorrect:

Incorrect, a flame test can be used in this experiment to identify cations


X Close

Problem Solving Strategy You will need to develop an effective strategy to identify your unknowns. Answer the

following questions to demonstrate your understanding.

The presence of some compounds can be determined by the color of the solution. Which of the following compounds are correctly matched with their corresponding color in solution?a.) Iron- Red/Orange, Cobalt-Pink, Copper-Blue

b.) Iron- Red/Orange, Cobalt- blue, Copper-blue

c.) Barium-Yellow, Iron- Red/Orange, Cobalt-Pink

Correct


X CloseIncorrect:

This answer is incorrect, Re-examine both Iron and Cobalt


X CloseIncorrect:

Incorrect, take another look at barium


X Close

Your Turn

• Now it is your turn to explore the reactive properties of the 9 different chemicals in this experiment. You may mix any combination of chemicals together as many times as you need to prepare yourself for the second portion of the lab. Use the problem solving strategies outlined previously and don’t forget to keep good notes of all of the reactive properties you observe.

Mg(NO3)2 NaSO4

CuSO4 Fe(NO3)3

Click on one of the above reagents to mix it with another reagent or click on the flame test button to see the results of a flame test using that solution. Keep

careful notes of what reagents you are mixing and the results of each reaction. You will use this information in the second part of this lab.

AgNO3 Pb(NO3)2 LiOH BaCl2 CoSO4

Flame test Flame test Flame test Flame test Flame test Flame test Flame test

Flame test Flame test

AgNO3 Pb(NO3)2 LiOH BaCl2 CoSO4 Mg(NO3)2 NaSO4 CuSO4

Fe(NO3)3

Choose which chemical you want to mix with Fe(NO3)3 and click on it to see the results.

Click back to return to main selection page

Fe(NO3)3

AgNO3

Yield: brownish/red solution; no precipitate

Click back to return to selection page

Fe(NO3)3

Pb(NO3)2



Fe(NO3)3

BaCl2



Fe(NO3)3

CoSO4

Yield: salmon solution; no precipitate


Fe(NO3)3

LiOH

Yield: clear solution; rust colored precipitate


Woah! A precipitate has formed. Write the complete ionic equation and the net ionic equation of the reaction in your notebook. Be sure to pay attention to charges!

Click close to return

X Close

Fe(NO3)3

Mg(NO3)2



Fe(NO3)3

NaSO4



Fe(NO3)3

AlCl3



Fe(NO3)3

CuSO4

Yield: brown solution; no precipitate


AgNO3 Pb(NO3)2 LiOH BaCl2 CoSO4 Mg(NO3)2 NaSO4 Fe(NO3)3

CuSO4

Choose which chemical you want to mix with CuSO4 and click on it to see the results.


CuSO4

AgNO3

Yield: blue solution; white precipitate




X Close

CuSO4

Pb(NO3)2





X Close

CuSO4

LiOH

Yield: clear solution; blue/green precipitate




X Close

CuSO4

BaCl2





X Close

CuSO4

CoSO4

Yield: purple solution; no precipitate


CuSO4

Mg(NO3)2

Yield: blue solution; no precipitate


CuSO4

NaSO4



CuSO4

AlCl3



CuSO4

Fe(NO3)3

Yield: brown solution; no precipitate


AgNO3 Pb(NO3)2 LiOH BaCl2 CoSO4 Mg(NO3)2 CuSO4Fe(NO3)3

NaSO4

Choose which chemical you want to mix with NaSO4 and click on it to see the results.


Na(SO4)

AgNO3

Yield: clear solution; white precipitate




X Close

Na(SO4)

Pb(NO3)2





X Close

Na(SO4)

LiOH

Yield: clear solution; no precipitate


Na(SO4)

BaCl2





X Close

Na(SO4)

CoSO4

Yield: pink solution; no precipitate


Na(SO4)

Mg(NO3)2



Na(SO4)

AlCl3



Na(SO4)

CuSO4



Na(SO4)

Fe(NO3)3

Yield: brownish red solution; no precipitate


AgNO3 Pb(NO3)2 LiOH BaCl2 CoSO4 NaSO4 CuSO4Fe(NO3)3

Mg(NO3)2

Choose which chemical you want to mix with Mg(NO3)2 and click on it to see the results.


Mg(NO3)2

AgNO3



Mg(NO3)2

Pb(NO3)2



Mg(NO3)2

LiOH





X Close

Mg(NO3)2

BaCl2



CoSO4

Yield: pink solution; no precipitate


Mg(NO3)2

Mg(NO3)2

NaSO4



Mg(NO3)2

AlCl3



CuSO4



Mg(NO3)2

Fe(NO3)3



Mg(NO3)2

AgNO3 Pb(NO3)2 LiOH BaCl2Mg(NO3)2 NaSO4 CuSO4Fe(NO3)3

CoSO4

Choose which chemical you want to mix with CoSO4 and click on it to see the results.


CoSO4

AgNO3

Yield: light pink solution; white precipitate




X Close

CoSO4

Pb(NO3)2





X Close

CoSO4

LiOH





X Close

CoSO4

BaCl2





X Close

CoSO4

Mg(NO3)2

Yield: light pink solution; no precipitate


CoSO4

NaSO4



CoSO4

AlCl3



CoSO4

CuSO4

Yield: purple solution; no precipitate


CoSO4

Fe(NO3)3

Yield: salmon colored solution; no precipitate


AgNO3 Pb(NO3)2 LiOH CoSO4Mg(NO3)2 NaSO4 CuSO4Fe(NO3)3

BaCl2

Choose which chemical you want to mix with ZnCl2 and click on it to see the results.


AgNO3



BaCl2



X Close

Pb(NO3)2



BaCl2



X Close

LiOH



BaCl2



X Close

CoSO4



BaCl2



X Close

Mg(NO3)2



BaCl2

NaSO4



BaCl2

Woah! A precipitate has formed. Write the complete ionic equation of the reaction in your notebook. Be sure to pay attention to valence!


X Close

AlCl3



BaCl2

CuSO4



BaCl2



X Close

Fe(NO3)3



BaCl2

AgNO3 Pb(NO3)2 BaCl2 CoSO4Mg(NO3)2 NaSO4 CuSO4Fe(NO3)3

LiOH

Choose which chemical you want to mix with LiOH and click on it to see the results.


LiOH

AgNO3

Yield: clear solution; black/brown precipitate


LiOH

Pb(NO3)2





X Close

BaCl2



LiOH



X Close

CoSO4

Yield: clear solution; rose/red precipitate


LiOH



X Close

Mg(NO3)2



LiOH



X Close

NaSO4



LiOH

AlCl3



LiOH



X Close

CuSO4

Yield: clear solution; blue/green precipitate


LiOH



X Close

Fe(NO3)3

Yield: clear solution; rust colored precipitate


LiOH



X Close

AgNO3 LiOH BaCl2 CoSO4Mg(NO3)2 NaSO4 CuSO4Fe(NO3)3

Pb(NO3)2

Choose which chemical you want to mix with Pb(NO3)2 and click on it to see the results.


AgNO3



Pb(NO3)2

LiOH



Pb(NO3)2



X Close

BaCl2



Pb(NO3)2



X Close

CoSO4



Pb(NO3)2



X Close

Mg(NO3)2



Pb(NO3)2

NaSO4



Pb(NO3)2



X Close

AlCl3



Pb(NO3)2



X Close

CuSO4



Pb(NO3)2



X Close

Fe(NO3)3



Pb(NO3)2

Pb(NO3)2 LiOH BaCl2 CoSO4Mg(NO3)2 NaSO4 CuSO4Fe(NO3)3

AgNO3

Choose which chemical you want to mix with AgNO3 and click on it to see the results.


Pb(NO3)2



Ag(NO3)

LiOH

Yield: clear solution; black/brown precipitate


Ag(NO3)

BaCl2



Ag(NO3)



X Close

CoCl2



Ag(NO3)



X Close

Mg(NO3)2



Ag(NO3)

NaSO4



Ag(NO3)



X Close

AlCl3



Ag(NO3)



X Close

CuSO4



Ag(NO3)



X Close

Fe(NO3)3



Ag(NO3)

introduction welcome to the virtual lab simulation of a common qualitative analysis lab. the goal of...

Documents

x close slide

solubility rules nitrates

mind solubility rules

x close incorrect

solubility information

x close correct

unknown chemicals

animation slide