Search found 202 matches

by Dhamnekar Winod
Wed Nov 17, 2021 9:38 am
Forum: Chemistry forum
Topic: Question on structure of atom
Replies: 0
Views: 69

Question on structure of atom

An x-ray photoelectron spectroscopy experiment with an unidentified element, X, displays an emission spectrum with four distinct kinetic energies: 5.9 × 10⁻¹⁷ J,2.53 × 10⁻¹⁸ , 2.59 × 10⁻²⁰ J, 2.67 × 10⁻²⁰ (Assume the incident light has sufficient energy to eject any electron in the atom.) (a)Name al...
by Dhamnekar Winod
Sat Oct 30, 2021 12:20 am
Forum: Chemistry forum
Topic: Differences between electrolytic cells and voltaic cells
Replies: 5
Views: 144

Re: Differences between electrolytic cells and voltaic cells

ORPtable.png
ORPtable.png (227.32 KiB) Viewed 122 times
After reading above table, we can say E°/V for the reaction Zn(s) → Zn²⁺(aq) + 2 e⁻ is +0.76. Is this tabulated information wrong?
by Dhamnekar Winod
Fri Oct 29, 2021 9:57 pm
Forum: Chemistry forum
Topic: Differences between electrolytic cells and voltaic cells
Replies: 5
Views: 144

Re: Differences between electrolytic cells and voltaic cells

In Daniell cell, which is also called voltaic cell or galvanic cell, Redox reaction takes pace as follows: O: Zn(s) → Zn²⁺(aq) + 2e⁻ E°/V= +0.76 Anode with (-) sign R: Cu²⁺(aq) + 2e⁻ → Cu(s) E°/V = 0.34 Cathode with (+) sign Add the half-reactions together. The two half-reactions can be combined jus...
by Dhamnekar Winod
Thu Oct 28, 2021 8:24 am
Forum: Chemistry forum
Topic: Differences between electrolytic cells and voltaic cells
Replies: 5
Views: 144

Differences between electrolytic cells and voltaic cells

Voltaic Cells a)Do not require a power source. b)Convert chemical potential energy into electrical energy. c)The redox reaction is spontaneous. (The cell potential is positive and the change in Gibb's free energy is negative) d)The reaction with the lower standard reduction potential is utilized as ...
by Dhamnekar Winod
Thu Oct 21, 2021 9:48 am
Forum: Chemistry forum
Topic: Rate laws of reactions
Replies: 3
Views: 147

Re: Rate laws of reactions

Author of my chemistry notes explains as follows:

Rusting is a heterogeneous process. Iron powder has a greater surface area than a iron nail of a same mass. Therefore , agents responsible for rusting may attack more iron sites at the same time on the iron powder sample.
by Dhamnekar Winod
Thu Oct 21, 2021 8:16 am
Forum: Chemistry forum
Topic: Rate laws of reactions
Replies: 3
Views: 147

Rate laws of reactions

Iron powder rusts at a much faster rate than an iron nail.

Is this statement true?
If yes, what is your explanation?
If no, what is your explanation?
by Dhamnekar Winod
Thu Oct 21, 2021 1:06 am
Forum: Chemistry forum
Topic: Rate law question
Replies: 1
Views: 117

Rate law question

(A)The rate law for a certain gaseous reaction is Rate=k[A][C]. If the pressure in the reaction vessel is halved and all other conditions remains the same, the rate of the reaction is decreased by a factor of (a) 1 (b) 2 (c) 0.5 (d) 0.1 My answer is (a). Is this answer correct? if yes, why it is cor...
by Dhamnekar Winod
Sun Oct 17, 2021 10:12 pm
Forum: Chemistry forum
Topic: Highest boiling points
Replies: 2
Views: 141

Re: Highest boiling points

Very detailed answer, Thank you.
by Dhamnekar Winod
Sun Oct 17, 2021 8:07 am
Forum: Chemistry forum
Topic: Highest boiling points
Replies: 2
Views: 141

Highest boiling points

Boiling point and melting point: The minor difference between the electronegativities of hydrogen and carbon means that the bond between both of them is only weakly polar. If two alkanes having the same molecular weights are there then the highly branched one will have the lower boiling point. The m...
by Dhamnekar Winod
Wed Sep 29, 2021 7:37 am
Forum: Chemistry forum
Topic: Enthalpy of reaction using one equation and its enthalpy
Replies: 4
Views: 2217

Re: Enthalpy of reaction using one equation and its enthalpy

Your answer looks correct. Thank you.
by Dhamnekar Winod
Mon Sep 13, 2021 10:23 am
Forum: Chemistry forum
Topic: Equivalent based questions (Valency Factors)
Replies: 7
Views: 5240

Re: Equivalent based questions (Valency Factors)

I think my answer to a) is wrong. Your answer 75 ml of K2Cr2O7 is correct. But I have another answer as well 2) Using this formula v.f.1 × M1 × volume1= v.f.2× M2 × volume2 Plugging in the values available with us into this formula, we have 6×0.2M× V1=2×0.3M × 50 ml = 25 ml of Potassium Dichromate W...
by Dhamnekar Winod
Mon Sep 13, 2021 4:05 am
Forum: Chemistry forum
Topic: Equivalent based questions (Valency Factors)
Replies: 7
Views: 5240

Re: Equivalent based questions (Valency Factors)

Answer to a) Redox equation is K2Cr2O7 + 6Na2C2O4 + 14H^+ → 12CO2 + 2Cr + 2K^+ + 12Na^+ + 7H2O From the aforesaid redox equation, we can say that to oxidize 6 moles of Na2C2O4 (Sodium Oxalate), one mole of Potassium Dichromate (K2Cr2O7) is required. So, for 0.3M Sodium Oxalate 0.05 M Potassium Dich...
by Dhamnekar Winod
Sat Sep 11, 2021 7:42 am
Forum: Chemistry forum
Topic: Equivalent based questions (Valency Factors)
Replies: 7
Views: 5240

Re: Equivalent based questions (Valency Factors)

My attempt to answer all these questions: a) 75 mL of 0.2M K2Cr2O7 is required to oxidize 50 mL of 03M Na2C2O4 in acidic medium. b) 0.4 mole of KMnO4 is required to react completely with 1 mole of K2C2O4 in acidic medium. c) 120 mL of 0.1M KMnO4 is required to oxidize 100 mL of 0.3M FeC2O4 in acidic...
by Dhamnekar Winod
Sat Sep 11, 2021 1:15 am
Forum: Chemistry forum
Topic: Equivalent based questions (Valency Factors)
Replies: 7
Views: 5240

Equivalent based questions (Valency Factors)

a) What volume of 0.2 M K2Cr2O7 is required to oxidize 50 ml of 0.3 M Na2C2O4 in acidic medium? b)How many moles of KMnO4 will be required to react completely with 1 mole of K2C2O4 in acidic medium? c) What volume of 0.1 M KMnO4 is required to oxidize 100 ml of 0.3M FeC2O4 (Ferrous Oxalate) in acidi...
by Dhamnekar Winod
Sat Sep 11, 2021 12:58 am
Forum: Chemistry forum
Topic: What is gold number here?
Replies: 4
Views: 3845

Re: What is gold number here?

Yes, your answer is correct.