P Block Elements

Step 1: Reaction of Zn with NaOH. When zinc reacts with excess sodium hydroxide (NaOH), zinc hydroxide is formed. This is a white precipitate.
Step 2: Conclusion. Thus, the correct answer is .

Step 1: Hybridization of Te in TeCl₆.
The central atom in TeCl₆ undergoes sp³d hybridization due to the presence of five bonds (four chlorine atoms and one lone pair).

Step 2: Conclusion.
Thus, the correct hybridization is sp³d, so the correct answer is option (B).

Final Answer:

Step 1: Identify reagent nature.
PhMgBr is a Grignard reagent, behaves as nucleophile.
PCl is electrophilic at phosphorus.
Step 2: Substitution of Cl atoms by phenyl group.
Each chloride in PCl can be replaced by phenyl group from Grignard reagent.
So overall:

Step 3: Product formed.
The product is triphenylphosphine (PPh ).
Final Answer:

Step 1: Identify the geometry of PCl .
PCl has trigonal bipyramidal geometry.
Step 2: Axial and equatorial positions.
- 3 equatorial Cl atoms lie in one plane, separated by .
- 2 axial Cl atoms are perpendicular to the equatorial plane.
Step 3: Bond angles.
Equatorial--equatorial angle = .
Axial--equatorial angle = .
Step 4: Conclude.
Thus Cl--P--Cl angles are and .
Final Answer:

Step 1: Write reaction of with dilute NaOH.

So gaseous product (oxygen difluoride).
Step 2: Determine shape of .
Central atom is oxygen.
O has 2 bond pairs and 2 lone pairs bent structure like .
Step 3: Compare bond angle.
Bond angle in is .
In , fluorine is more electronegative, pulling bonding pairs away, reducing repulsion.
So bond angle is less than water: around .
Final Answer:

Step 1: Structure of .
In , xenon forms three double bonds.
Each double bond contains one -bond.
So total -bonds:

Step 2: Structure of .
In , xenon forms four bonds in tetrahedral structure.
Each has one -bond.
So total -bonds:

Final Answer:

Step 1: Identify sulphuric anhydride.
Sulphuric anhydride is .
Step 2: Structure and bonding of .
In , sulphur forms three sigma bonds.
So number of sigma bonds:

Step 3: Nature of -bonding.
In , -bonding involves overlap of oxygen -orbitals with sulphur -orbitals ( ) and one bond has character due to resonance.
Thus total:
- One bond
- Two bonds
Final Answer:

Step 1: Identify which oxyacids can contain bonds.
Oxyacids having more than one phosphorus atom may have linkage.
Step 2: Analyze options.
- , , contain single P no bond.
- has linkage, not .
- is hypophosphoric acid and contains bond.
Step 3: Correct pair.
So pair containing bond is:

Final Answer:

Step 1: Hydrolysis of .

So:

Step 2: Dehydration at high temperature.
At , silicic acid loses water to form silica:

So:

Final Answer:

Superoxides are the species having an bond and in an oxidation state of (superoxide ion is ).
Usually these are formed by active metals such as and .
For the salts of larger anions (like ), lattice energy increases in a group.
Since, lattice energy is the driving force for the formation of an ionic compound and its stability, the stability of the superoxides from ' ' to ' ' also increases.

Step 1: Understand the reaction.
Manganese dioxide (MnO ) dissolves in water to form Mn , which imparts a red color to the solution.
Step 2: Conclusion.
Therefore, the color of the acid formed when MnO dissolves in water is red.
Final Answer:

dissolves in water to give permanganic acid which is purple in colour.

Basic oxides are oxides of metals that react with water to form bases. Among the given options, is the strongest basic oxide.

The amphoteric character of is shown by its ability to react both with acids and bases. Set I and Set III represent reactions where acts as an acid (reacting with OH-) and a base (reacting with ).

When and react with excess water, they form phosphoric acid as the primary product.

Step 1: Analyzing the Reactions.
The reaction in (B) involves the formation of xenon and oxygen, which is not feasible under normal conditions. Xenon compounds typically do not reduce to elemental xenon under such conditions.
Step 2: Conclusion.
The correct answer is (B), as this reaction is not feasible.

Step 1: Disproportionation of .
When xenon tetrafluoride ( ) is disproportionated in water, it gives xenon tetroxide ( ) and hydrofluoric acid (HF) as products. This is a typical disproportionation reaction of xenon compounds.
Step 2: Conclusion.
The correct answer is (C), and HF.

Step 1: Understand the structure of the oxy-acids.
Among the given options, (phosphorous acid) has three hydrogens directly attached to phosphorus. This is the maximum among the oxy-acids listed.
Step 2: Conclusion.
Thus, the correct answer is .
Final Answer:

Step 1: Analyze the electron pairs.
The maximum number of lone pairs in xenon compounds occurs in XeF because it has the highest coordination number and thus the most lone pairs.
Step 2: Conclusion.
Thus, XeF has the maximum number of lone pairs.
Final Answer:

Step 1: The thermal stability of hydrogen halides increases as we go down the group due to weaker H-X bonds.
Step 2: is the most stable due to the weakest bond, and is the least stable due to the strong H-F bond.

Final Answer:

Step 1: Heating (potassium dichromate) with NaCl and concentrated sulfuric acid results in the formation of chromium chloride ( ) and chlorine gas.
Step 2: The correct product from this reaction is .

Final Answer:

Phosphine ( ) is generally prepared by heating white phosphorus with an aqueous solution of caustic potash. This process produces phosphine gas.
Final Answer:

Manganese (Mn) is capable of forming a large number of oxides, ranging from +2 to +7 oxidation states, which makes it the element with the maximum number of oxides.
Final Answer:

The number of lone pairs on Xe varies based on the molecule's structure. and have the same number of lone pairs, while has a different number.
Final Answer:

An oxygen- helium mixture is used for artificial respiration in deep sea diving instead of air because nitrogen present in air dissolves in blood under high pressure when sea diver goes into deep sea. When he comes to the surface nitrogen bubbles out of the blood due to decrease in pressure, causing pain. This disease is called "bends".

Both and are coloured ions in aqueous solutions, whereas and are colourless.

Step 2: Conclusion.
Thus, the correct answer is (4) .

Step 1: Stepwise analysis.
- The reaction with P converts ethanol to an aldehyde (propanal). - The reaction with Mg/ether forms a Grignard reagent. - The reaction with formaldehyde results in a secondary alcohol (butanol). - The final reaction with water gives n-propyl alcohol.

Step 2: Conclusion.
Thus, compound D is n-propyl alcohol.

The secondary structure of a protein refers to the regular folding of continuous portions of the polypeptide chain, such as alpha-helices and beta-pleated sheets.

Step 2: Conclusion.
Thus, the correct answer is (4) regular folding patterns of continuous portions of the polypeptide chain.

Step 1: Analyze the reactions.
We are given two reactions. To calculate the total number of atoms, we need to balance the elements in the reactants and products.

Step 2: Calculate the total number of atoms.
In one molecule of each compound (A), (B), and (C), we calculate the sum of the atoms involved. The total comes out to be 18.

Step 1: Use the formula for density.
The density of a cubic unit cell is given by: where is the number of atoms per unit cell, is the molar mass, is Avogadro's number, and is the volume of the unit cell.

Step 2: Calculate the radius.
Using the given values for , , and the unit cell edge length, we find the radius of the metal atom to be 217 pm.

Nitrous oxide (N O) produces a laughing sensation when inhaled.