Class notes
Qualitative analysis of redox reactions
- Course
- Institution
Written with Virtual high school (VHS)
[Show more]
Seller
Follow
studystar9touni
Content preview
Table 1:Ion (hydrated) +
VO2 (𝑎𝑞)
2+
𝑉𝑂 (𝑎𝑞)
3+
𝑉 (𝑎𝑞)
2+
𝑉 (𝑎𝑞)
Colour Yellow Blue Green Violet
Name Dioxovanadium Oxovanadium Vanadium (III) Vanadium (II)
(V) (IV)
Oxidation state +2 +3 +2
Table 2:
Test Observations
Dioxovanadium (V) + sulfite Yellow solution turned into a blue solution.
Dioxovanadium (V) + zinc Yellow solution turned into green solution
after 20 seconds, blue solution after 1 minute,
green solution after 7 minutes and violet
solution after 25 minutes.
Dioxovanadium (V) + iodide + thiosulfate Yellow solution turned orange after potassium
iodide was added and turned blue after
sodium thiosulphate was added.
Vanadium (II) + permanganate Purple solution turned green, blue, green,
yellow and violet with an increase of
permanganate added.
Questions:
1) The green color from the second test occurred because vanadium has many oxidation states.
When zinc was added to dioxovanadium, dioxovanadium oxidized to become vanadium (III)
which is green in color.
In which test(s) was vanadium reduced? Vanadium was reduced in test 2 when the green solution
of 20 seconds was changed to blue solution of 1 minute. Vanadium was also reduced in test 4
when the green solution of first drops changed to blue with added permanganate. Vanadium was
also reduced a few times in test 4.
In which test(s) was vanadium oxidized? Vanadium was oxidized in test 1, test 2 except for blue
solution, test 3 except for orange and test 4 a few times.
Which species is the stronger reducing agent: Sulphite or zinc? How do you know? Zinc is the
stronger reducing agent. In the test with sulphite, the yellow solution turned to blue which
indicates oxidation and this is the only experiment shared with us. In an experiment with zinc,
the green solution turned to blue which indicates reduction.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller studystar9touni. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $2.20. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67474 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now