Multiple Choice QuestionsThe heat liberated when 1.89 g of benzoic acid is burnt in a bomb calorimeter at 25°C and it increases the temperature of 18.94 kg of water by 0.632°C. If the specific heat of water at 25°C is 0.998 cal/g-deg, the value of the heat of combustion of benzoic acid is
881.1 kcal
771.2 kcal
981.1 kcal
871.2 kcal
Which of the following alkenes will give same product by any method out of hydration, hydroboration-oxidation and oxymercuration-demercuration?
CH3CH=CH2
CH3CH=CHCH3
CH3CH(CH3)CH=CH2
The compound formed by the ozonolysis of acetylene :
glycol
acetic acid
ethylene ozonide
glyoxal
Assertion : Staggered conformation of ethane is 12.5 kJ mol-1 more stable than the eclipsed conformation.
Reason : The two conformations of ethane cannot be separated at room temperature.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
B.
If both assertion and reason are true but reason is not the correct explanation of assertion
Staggered conformation is more stable because in this conformation any two hydrogen atoms on adjacent carbon atoms are as far apart as possible and the repulsion between the electron clouds of - bonds of two non-bonded hydrogen atoms is minimum.
The energy difference of 12.55 kJ mol-1 is not large enough to prevent rotation at room temperature as a result it is not possible to seperate the two conformations of ethane.
The C-H bond energy in ethane , ethene and ethyne :
more in ethene
more in ethane
more in ethyne
same in all these
The IUPAC name of the given compound is (CH3)3CCH2C(CH3)3
2, 3,4,4-tetramethylpentane
1, 2, 2, 4-tetramethylpentene
2,2,4, 4-tetramethylpentane
3, 3-dimethylpentane.
Assertion: Saturated hydrocarbons are chemically less reactive.
Reason : All isomeric paraffins have same parent name.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Chloroform is stored in dark coloured bottles.
Reason: Chronic chloroform exposure may cause damage to liver and kidneys.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
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