State (Phase) of Alkanes

Q. What is octane number and how to find it❓

Q. Dihedral angle of least stable conformer of ethane is :

1. $0^{\circ }$
2. ${120}^{\circ }$
3. ${180}^{\circ }$
4. $60^{\circ }$

Q. The alkane which has only primary hydrogen atom is

1. Pentane
2. Isopentane
3. Neopentane
4. 2, 2-Dimethylpentane

Q. The bond line structure of 2, 3-dimethylbutane is

1. 
2. 
3. 
4. 
   

Q. What is Octane number in organic chemistry ?

Q. Which of the following compounds are not soluble in water?

1. Formaldehyde
2. Acetaldehyde
3. Acetone
4. All the above are soluble

Q. Which one of the following is formed (mainly) when red phosphorus is heated in a sealed tube at 803 K?

1. Yellow phosphorous
2. $\alpha$-Black phosphorus
3. $\beta$-Black phosphorus
4. White phosphorus

Q.

Sodium is a very reactive metal. Is the statement true or false?

1. True
2. False

Q.

Rotation around carbon - carbon single bond of ethane is not completely free. Discuss.

Q.

Name the following

A metal that gives a lilac flame.

Q.

Name the metal which burns in the air with a golden flame?

Q. With increase in the number of carbon atoms in alkanes, the physical state changes from.

1. Solid, Liquid, Gas.
2. Gas, Liquid, Solid.
3. Solid, Gas, Liquid.
4. Gas, Solid, Liquid.

Q.

The number of P-O-P bonds in Pyrophosphoric acid is:

1. Zero

2. Four

3. One

4. Three

Q.

Cyclohexane, a hydrocarbon, floats on water because

1. Its immiscible with water

2. Its density is low as compared to water

3. Both (b) & (d)

4. Its immiscible & lighter then water

Q.

Is methane an alkane?

Q. Arrange the following in decreasing order of their boiling points.
(I) n-Butane
(II) 2-Methylbutane
(III) n-Pentane
(IV) 2, 2-Dimethylpropane

1. II > III > IV > I
2. IV > III > II > I
3. III > II > IV > I
4. I > II > III > IV

Q.

Describe hydrocarbon products.

Q. Between methane ethane and Acetylene which will have greater calorific value explain very detailed

Q. $C{F}_4$ has a greater bond angle than $C{H}_4$.

1. True
2. False

Q.

What is denaturation?

Q. Correct order of Boiling point for
(i) I – Chloropropane (ii) Isopropyl chloride (iii) 1-Cholor butane

1. (i) < (ii) < (iii)
2. (ii) > (i) > (iii)
3. (ii) < (i) < (iii)
4. (i) > (ii) > (iii)

Q. Assertion :Boiling point of pentane is higher than 2, 2-dimethylpropane. Reason: There is steady increase in boiling point with increase in molecular mass.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

Is kerosene a hydrocarbon?

Q. Arrange the following according to the increasing order of the melting point.

1. $I<II<III<IV$
2. $I>II<III<IV$
3. $I>II>III>IV$
4. $I<II>III>IV$

Q. What effect does branching of an alkane chain has on its melting point ?

1. Increases its melting point
2. Decreases its melting point
3. doesn't change its melting point
4. Cannot be determined

Q. Which of the following molecules has the shortest carbon-carbon single bond length?

1. $C{H}_2$=$CH-C-C{H}_3$
2. $C{H}_2$=$CH-C=N$
3. $C{H}_2$=$CH-C=O$
4. $C{H}_2$=$CH-CH$=$C{H}_2$

Q. A fuel has the same knocking property as a mixture of 70% iso-octane (2, 2, 4-trimethylpentane) and 30% n-heptane by volume. The octane number of the fuel is:

1. 100
2. 70
3. 50
4. 40

Q. How many number of $1^{\circ },2^{\circ }and{3}^{\circ }$ carbon atoms in the following compounds ?

1. 3, 2, 2
2. 3, 2, 1
3. 3, 1, 2
4. 2, 2, 2

Q. Choose the correct statement for the given $S_{N}2$ reaction.

1. $F$ gets replaced, S is absolute configuration of product
2. $Br$ gets replaced, R is absolute configuration of product
3. $Br$ gets replaced, S is absolute configuration of product
4. $F$ gets replaced, R is absolute configuration of product

Q. Which of the following statement is correct regarding stability of the parent alkenes and the product alkenes?

1. All alkenes are equally stable
   
2. Alkene III is more stable than I and II
   
3. All alkenes are equally stable
   
   
4. Alkene IIIa ia more stable than Ia and IIa