General Properties

Q. X-ray diffraction studies show that copper crystallises in an fcc unit cell with cell edge of $3.608\times {10}^{-8}$ cm. In a separate experiment, copper is determined to have a density of $8.92mc{m}^{-3}$, calculate the atomic mass of copper.

Q. What is the enthalpy of bond dissociation per kilojoule mole inverse at 298.2 Kelvin of tritium?

Q. The radii which represents half of the distance between two similar atoms in separate molecules in a solid is known as

1. Covalent radius
2. van der Waal's radius
3. Metallic radius
4. Ionic radius

Q. Melting point of polonium is less than that of tellurium.

1. True
2. False

Q. Which of the following is not a chalcogen

1. S
2. Se
3. Na
4. O

Q. The correct sequence of bond enthalpy of $C-X$ bond is

1. $C{H}_3-F<C{H}_3-Cl<C{H}_3-Br<C{H}_3-I$
2. $C{H}_3-F>C{H}_3-Cl>C{H}_3-Br>C{H}_3-I$
3. $C{H}_3-F<C{H}_3-Cl>C{H}_3-Br>C{H}_3-I$
4. $C{H}_3-Cl>C{H}_3-F>C{H}_3-Br>C{H}_3-I$

Q. Consider the following statements for Zn²⁺ complexes
(I) In Zn²⁺ complexes, zinc has 3d¹⁰ outermost electronic configuration
(II) Zn²⁺ shows d-d transition
(III) Zn²⁺ with coordination number four shows tetrahedral geometry.
Which of the following option contains the correct set of statement(s)?

Zn²⁺ संकुलों के लिए निम्नलिखित कथनों पर विचार कीजिए।
(I) Zn²⁺ संकुलों में, जिंक का बाह्यतम इलेक्ट्रॉनीय विन्यास 3d¹⁰ होता है
(II) Zn²⁺ d-d संक्रमण दर्शाता है
(III) चार समन्वय संख्या वाले Zn²⁺ चतुष्फलकीय ज्यामिति दर्शाते हैं
निम्नलिखित में से किस विकल्प में कथन/कथनों का सही समुच्चय है?

1. I, II, III
2. Only I, III
   
   केवल I, III
3. Only II, III
   
   केवल II, III
4. Only I
   
   केवल I

Q.

Write any two uses of the following metalloid.

Boron

Q.

The most abundant nonmetal (discount metalloids) on the earth’s crust is

__

Q.

The bond order of ${\mathrm{O}}_2$ is?

1. $1$

2. $2$

3. $1.5$

4. $3$

Q. This section contains 1 Assertion-Reason type question, which has 4 choices (a), (b), (c) and (d) out of which ONLY ONE is correct.

इस खण्ड में 1 कथन-कारण प्रकार का प्रश्न है, जिसमें 4 विकल्प (a), (b), (c) तथा (d) दिये गये हैं, जिनमें से केवल एक सही है।

A : KMnO₄ when heated produces K₂MnO₄, which is insoluble in water.

A : KMnO₄ को गर्म करने पर K₂MnO₄ प्राप्त होता है, जो जल में अविलेयशील है।

R : KMnO₄ when boiled in basic solution, forms K₂MnO₄.

R : KMnO₄ को क्षारीय विलयन में उबालने पर K₂MnO₄ बनता है।

1. Both (A) and (R) are true and (R) is the correct explanation of (A)
   
   (A) तथा (R) दोनों सही हैं तथा (R), (A) का सही स्पष्टीकरण है
2. Both (A) and (R) are true but (R) is not the correct explanation of (A)
   
   (A) तथा (R) दोनों सही हैं लेकिन (R), (A) का सही स्पष्टीकरण नहीं है
3. (A) is true but (R) is false
   
   (A) सही है लेकिन (R) गलत है
4. (A) is false but (R) is true
   
   (A) गलत है लेकिन (R) सही है

Q. Which of the following is an example of a metalloid?

1. Neon
2. Hydrogen
3. Silicon
4. Lead

Q.

Strongest bond is formed by the head-on overlapping of:

1. 2s and 2p orbitals

2. 2p and 2p orbitals

3. 2s and 2s orbitals

4. All of these

Q. Bond angle of Group-16 hydrides decreases down the group and the bond angle of $H_{2}Te$ is approximately ${90}^0.$

1. False
2. True

Q. The correct order of the thermal stability of hydrogen halides $(H-X)$ is

1. $HI>HCl<HF>HBr$
2. $HCl<HF>HBr<HI$
3. $HF>HCl>HBr>HI$
4. $HI<HBr>HCl<HF$

Q. Give reasons for the two $S=O$ bonds in ${SO}_2$ are identical.

Q. "$N_2{H}_4$ is a kinetically stable compound."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.

Q. Given below are two statements:

Statement $I:$ $\alpha$ and $\beta$ forms of sulphur can change reversibly between themselves with slow heating or slow cooling.

Statement $II:$ At room temperature the stable crystalline form of sulphur is monoclinic sulphur.

In the light of the above statements, choose the correct answer from the options given below.

1. Both statement $I$ and statement $II$ are false
2. Statement $I$ is true but statement $II$ is false
3. Both statement $I$ and statement $II$ are true
4. Statement $I$ is false but statement $II$ is true

Q. Which of the following bonds has the highest energy?

1. Se-Se
2. Te-Te
3. S-S
4. O-O

Q. Which of the following bonds has the highest energy?

1. $S-S$
2. $O-O$
3. $Se-Se$
4. $Te-Te$

Q. Melting point of polonium is less than that of tellurium.

1. True
2. False

Q. $S_2{O}_8$ have :

1. S-S bond
2. S-O bridge
3. O-O bridge
4. None of the above

Q. The highest catenation ability is shown by

1. Sulphur
2. Carbon
3. Oxygen
4. Tellurium

Q. Which is the correct thermal stability order
for $H_{2}E$ $(E=O,S,Se,TeandPo$)?

1. $H_{2}S$<$H_{2}O$<$H_{2}Se$<$H_{2}Te$<$H_{2}Po$
2. $H_{2}O$<$H_{2}S$<$H_{2}Se$<$H_{2}Te$<$H_{2}Po$
3. $H_{2}Po$<$H_{2}Te$<$H_{2}Se$<$H_{2}S$<$H_{2}O$
4. $H_{2}Se$<$H_{2}Te$<$H_{2}Po$<$H_{2}O$<$H_{2}S$

Q.

Which of the following bonds has the least energy?

1. Te – Te

2. Se – Se

3. S – S

4. O – O

Q. Name the elements of group $16$ which have:
highest catenation property

Q. The element that does not show catenation is :

1. Sn
2. Ge
3. Si
4. Pb

Q.

Among the chalcogens, the element that exhibits the highest tendency for catenation is:

1. Oxygen

2. Sulphur

3. Selenium

4. Tellurium

Q.

The most abundant nonmetal (discount metalloids) on the earth’s crust is

__

Q. Explain the trends in the following properties, with reference to group-16?