Cyanide is a notorious ion for its lethal use as a poison, both in historical ev

ID: 494563 • Letter: C

Question

Cyanide is a notorious ion for its lethal use as a poison, both in historical events, such as Jonestown, and in fictional settings, such as the works of Agatha Christie. Cyanide poisoning occurs by the ion binding with iron in your body and blocking essential biological functions, particularly the transportation of oxygen. Therefore, it is extremely important to be able to test for cyanide in any drink or drinking water source.

One qualitative test for cyanide is its almond-like scent. However, if the cyanide is in a flavored beverage, its scent might be masked. You need a more reliable test.

1.) Whether your test is successful or not, you should know how to respond to possible poisoning. Look up the First Aid Measures section of the SDS for potassium cyanide. If someone accidentally ingests (drinks) cyanide, should you induce vomiting?

a. no

b. yes

c. depends on the amount ingested

2.) Whether your test is successful or not, you should know how to respond to possible poisoning. Look up the First Aid Measures section of the SDS for potassium cyanide.

If someone accidentally ingests (drinks) cyanide, who should you contact?

Limit your answer to one or two words.

3.) Prussian blue can be made by heating a sample containing cyanide in a basic solution containing both iron(II) sulfate and iron(III) chloride, and then adding acid. The resulting compound is so blue that it was the basis for many blue paints.

This test (is / is not) practical for quickly detecting cyanide in drinks because it requires (sample destruction / heating / visiaul inpection for color / addition of chemicals), which is a (quick / slow) process.

4.) After a bit of research, you have learned that an easier test can be performed by first oxidizing cyanide ions with thiosulfate to form thiocyanate and sulfite ions. Write out the balanced net ionic reaction of cyanide with thiosulfate.

Your response should be the chemical equivalent of the following, where "#" is the stoichiometry. Use chemical formulas, and include any charges in the box with the ion. Include stoichiometry for each species, even if it is one.

5.) What is missing from the net ionic equation above? Hint: Will you be able to just add thiosulfate to your reaction?

Your answer should be a one or two word response to the prompt.

6.) The reaction of cyanide with thiosulfate has prepared the thiocyanate ion which, when in acidic solution, bonds to the iron ions in iron(III) nitrate to form a deep red solution. Describe the resulting two-step procedure, including all reagents.

Step 1) Add (acid / thiosulfate and iron (III) nitrate / iron(III) nitrate / thiosulfate compound / acid and iron(III) / thiosulfate compound and acid) to the cyanide sample.

Step 2) Add (thiosulfate and iron(III) nitrate / thiosulfate compound / acid / iorn(III) nitrate / thiosuldate compount and acid / acid and iron(III) nitrate) to the sample.

7.) Thiocyanate is so much less harmful than cyanide that adding thiosulfate is actually part of the treatment for cyanide poisoning. How can your test distinguish between the presence of thiocyanate and the presence of the lethal cyanide?

a. Upon addition of acid and iron(III) nitrate, thiocyanate will form a dark red solution while the cyanide will form a blue solution.

b. Thiocyanate can be dissociated under weak acidic conditions, then oxidized into carbonate, sulfate, and ammonia. A qualitative analysis test will detect any carbonate, sulfate, or ammonia. If the sulfate is present, you can conclude that there is thiocyanate but not cyanide.

c. Thiocyanate is less intense than cyanide, so when performing the test, if the result is stronger that means cyanide is present. If the result is weaker that means only thiocyanate is present.

d. The sample will need to be tested twice: once with thiocyanate and once without it. If a red color appears both times, thiocyanate is present, but not cyanide.

e. To distinguish the presence of cyanide with thiocyanate, a sulfate test can be done. If a precipitate forms, there is sulfur in the solution, and thiocyanate is present.

Explanation / Answer

No. You should not make them vomit if any one swallowed cyanide. Cyanide in their vomit could contaminate others, or damage their airway.

2.) If someone accidentally ingests (drinks) cyanide, who should you contact?

Call 911 or poison control at 800 222 1222 in USA

3.) Prussian blue can be made by heating a sample containing cyanide in a basic solution containing both iron(II) sulfate and iron(III) chloride, and then adding acid. The resulting compound is so blue that it was the basis for many blue paints.

This test is not practical for quickly detecting cyanide in drinks because it requires sample destruction, heating, visiaul inpection for color, addition of chemicals, which is a slow process.

1 cyanide(aq) + 1 thiosulfate(aq) =========è 1 thiocyanate(aq) + 1 sulfite(aq)

5.) What is missing from the net ionic equation above?

Counter ions for cyanide and thiosulfate

6.) The reaction of cyanide with thiosulfate has prepared the thiocyanate ion which, when in acidic solution, bonds to the iron ions in iron(III) nitrate to form a deep red solution. Describe the resulting two-step procedure, including all reagents.

Step 1) Add thiosulfate compound to the cyanide sample. The following reaction proceeds:

1 cyanide(aq) + 1 thiosulfate(aq) =========è 1 thiocyanate(aq) + 1 sulfite(aq)

Step 2) Add iron(III) nitrate to the sample which allows the following reaction.

thiocyanate + iron (III) nitrate + acid = deep red solution

a. Upon addition of acid and iron(III) nitrate, thiocyanate will form a dark red solution while the cyanide will form a blue solution

Navigate

Cyanide ions can be determined by indirect complexometry. An excess of Ni2+ is a

Cyanide is a poison that blocks the passage of electrons along the electron tran

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.

Cyanide is a notorious ion for its lethal use as a poison, both in historical ev

Question

Explanation / Answer

Related Questions

Navigate