Ncert Solutions Chemistry Class 12th
Get insights from 2.6k questions on Ncert Solutions Chemistry Class 12th, answered by students, alumni, and experts. You may also ask and answer any question you like about Ncert Solutions Chemistry Class 12th
Follow Ask QuestionQuestions
Discussions
Active Users
Followers
New answer posted
6 months agoContributor-Level 10
7.14
The enthalpy of dissociation of H-E bond (E= O, S, Se, Te, Po) in the hydrides decreases down the group. Hence, the thermal stability of the hydrides decreases down the group. The thermal stability is in the order H2O > H2S> H2Se> H2Te >H2Po.
New answer posted
6 months agoContributor-Level 10
7.13
Sulphur generally exists in the combined form in the following sulphate minerals like gypsum (CaSO4.2H2O), Epsom salt (MgSO4.7H2O), barite (BaSO4) and sulphide minerals such as galena (PbS), zinc blende (ZnS), copper pyrites (CuFeS2).
Traces of sulphur are present in volcanoes as hydrogen sulphide. Sulphur is also present in organic materials such as eggs, proteins, garlic, onion, mustard, hair, and wool.
New answer posted
6 months agoContributor-Level 10
7.12
H3PO3 on heating dissociates into orthophosphoricacid (H3PO4) and phosphine (PH3). Since, the oxidation states of orthophosphorous acid (H3PO3), orthophosphoric acid (H3PO4) and phosphine (PH3) are +3, +5 and -3 respectively, this reaction is known as a disproportionate reaction (since the oxidation states of one of the product are positive and the other is negative). The reaction is as follows.
New answer posted
6 months agoContributor-Level 10
7.11
The basicity of a compound is defined as the number of acidic hydrogen atoms present in the compound. For a hydrogen atom to be acidic, it should be bonded to a strongly electronegative element like fluorine or oxygen atom.
As shown in the figure, 3 hydrogen atoms (green circled) are attached to an oxygen atom, which makes them acidic. Hence, the basicity of H3PO4 is 3.
New answer posted
6 months agoContributor-Level 10
7.10
The balanced equation for the hydrolytic reaction of PCl5 in heavy water (D2O):
Therefore, on adding the above two equation we can say that the net reaction is:
New answer posted
6 months agoContributor-Level 10
7.9
Generally, in CCl4, all the C-Cl bonds are equal. But that is not in the case of PCl5. All the bonds in PCl5 are not similar. It has three equatorial and two axial bonds. Therefore, when PCl5 is heated strongly, the axial bonds breakdown and thus PCl5 decomposes to PCl3.
New question posted
6 months agoNew answer posted
6 months agoContributor-Level 10
7.8
White phosphorous when heated with concentrated NaOH solution (in a CO2 atmosphere) gives phosphine, PH3. Another product is Sodium hypophosphite, NaH2PO2.
New answer posted
6 months agoContributor-Level 10
7.7 Hybridisation of P in PH3 is sp3. Out of the four sp3 hybrid orbitals, three are involved in bonding with the three H-atoms and the fourth one has a lone pair in it.
PH3 when combines with a proton, it forms PH + in which the lone pair is absent. So, here all the four hybrid orbitals are involved in bonding.
Now; the lone pair- bond-pair repulsion is stronger than the corresponding bond pair-bond pair repulsion; thus, the tetrahedral shape associated with sp3 bonding in PH3 is changed to pyramidal and due to the absence of lone pair in PH4+, there is no lone pair-bond pair repulsion. Hence; the bond angle in PH4+ is higher than the b
New answer posted
6 months agoContributor-Level 10
7.6 Diagram of N2O5:
Covalence of nitrogen in N2O5 is 4 (as can be said from the above diagram).
Note: Covalence is the number of electron pairs that an atom can share with other atoms.
Taking an Exam? Selecting a College?
Get authentic answers from experts, students and alumni that you won't find anywhere else
Sign Up on ShikshaOn Shiksha, get access to
- 65k Colleges
- 1.2k Exams
- 679k Reviews
- 1800k Answers