Allotropes of Phosphorus

Q.

What are the uses of Lanthanides?

Q.

$P_4$ (white phosphorus) when treated with thionyl chloride produces phosphorus __________ . On the other hand if $P_4$ (white phosphorus) is treated with sulphuryl chloride we get phosphorus __________ .

Q.

What is the chemical name of ${\mathrm{Mn}}_3{\left({\mathrm{BO}}_3\right)}_2$?

Q.

What are the applications of lanthanides?

Q.

Why red phosphorus is used in safety matches?

Q.

Rain water has a pH of $5.6$due to the presence of:

Q.

What are the allotropes of phosphorus?

Q. Which of the following complex compounds will exhibit highest paramagnetic behaviour ?
(At.No. : $Ti=22,Cr=24,Co=27,Zn=30$)

1. $\left[Co\right(N{H}_3{)}_6{]}^{3+}$
2. $\left[Zn\right(N{H}_3{)}_6{]}^{3+}$
3. $\left[Cr\right(N{H}_3{)}_6{]}^{3+}$
4. $\left[Ti\right(N{H}_3{)}_6{]}^{3+}$

Q.

As the s-character of hybridized orbital decreases, the bond angle

1. Decreases

2. Increases

3. Does not change

4. Becomes zero

Q.

$P_4$ (white phosphorus) when treated with thionyl chloride produces phosphorus ___. On the other hand if $P_4$ (white phosphorus) is treated with sulphuryl chloride we get phosphorus ___.

Q.

What happens when we heat sulfur at a high temperature?

Q. On increasing the pressure, in which direction will the gas phase reaction proceed to re-establish equilibrium, is predicted by applying the Le Chatelier’s principle. Consider the reaction: $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$ .Which of the following is correct, if the total pressure at which the equilibrium is established, is increased without changing the temperature?

1. $K$ will increase initially and decrease when pressure is very high.
2. $K$ will increase
3. $K$ will decrease
4. $K$ will remain same

Q.

On combustion of Li, Na and K in excess of air, the major oxides formed, respectively, are

1. ${\mathrm{Li}}_2{\mathrm{O}}_2,{\mathrm{Na}}_2{\mathrm{O}}_2\mathrm{and}{\mathrm{K}}_2{\mathrm{O}}_2$

2. ${\mathrm{Li}}_2\mathrm{O},{\mathrm{Na}}_2{\mathrm{O}}_2\mathrm{and}{\mathrm{KO}}_2$

3. ${\mathrm{Li}}_2\mathrm{O},{\mathrm{Na}}_2\mathrm{O}\mathrm{and}{\mathrm{K}}_2{\mathrm{O}}_2$

4. ${\mathrm{Li}}_2\mathrm{O},{\mathrm{Na}}_2{\mathrm{O}}_2\mathrm{and}{\mathrm{K}}_2\mathrm{O}$

Q.

What are the properties of white phosphorus?

Q.

Chemical reactions in which heat is absorbed.

Q.

What is the structure of black phosphorus?

Q. After completion of the reactions (I and II), the organic compound(s) in the reaction mixtures is/are

1. Reaction I : P and reaction II: P
2. Reaction I: U, acetone and reaction II: Q, acetone
3. Reaction I: T, U acetone and reaction II: P
4. Reaction I: R, acetone and reaction II : S, acetone

Q. Pure silicon is an insulator. Silicon doped with phosphorus is a semiconductor. Silicon doped with gallium is also a semiconductor. What is the difference between the two doped semiconductors?

Q. The structure of (S)-2-Fluorobutane is best represented by :

1. 
2. 
3. 
4. 

Q.

Sir/ Madam

Whycan't ozone be a reducing agent?

The highest oxidation state of oxygen is +2 which is possible when it combines with fluorine. Now then, why can't ozone be a reducing agent?

What happens when ozone reacts with fluorine or fluorine containing compound?

Please explain in detail.

Q.

Which allotropic form of phosphorus glows in dark?

Q. Which of the elements listed below occurs in allotropic form

1. Iodine
2. Copper
3. Sulphur
4. Silver

Q. Silver Chloride is soluble in Methylamine due to the formation of

1. AgOH
2. [Ag(CH₃NH₂)₂]Cl
3. Ag + CH₃Cl + NH₄Cl
4. Ag(CH₃NH₂)Cl

Q. White phosphorus reacts with calcium to give a certain compound. This compound on hydrolysis produces:

1. P₂H₄
2. PH₃
3. P₄O
4. P₂

Q. In $P_4$ molecule phosphorus atoms are tetrahedrally arranged. The bond angle P-P-P in the molecule is

1. ${108}^{\circ }$
2. ${120}^{\circ }$
3. ${60}^{\circ }$
4. ${180}^{\circ }$

Q.

What are polyatomic molecules? Give an example.

Q. Which is the most stable allotropic form of phosphrous?

1. red
2. white
3. black
4. yellow

Q.

FeS is the chemical formula of

1. Iron Sulphate

2. Iron(II) sulphide

3. Iron (II) Sulphite

4. Iron (III) Sulphide.

Q. White phosphorus is a highly-reactive, molecular solid that melts just above room temperature (melting point = 30 degree Celsius). It subtly glows in the dark emitting light and this phenomenon is called chemiluminescence – True or False

1. True
2. False

Q.

How dangerous is Red phosphorous.