71. The mass of P4O10 that will be obtained from the reaction of 1.33 gram of P4 and 5.07 of oxygen is
A. 2.05 gram
B. 3.05 gram
C. 4.05 gram
D. 5.05 gram
✅ The correct answer is option B.
Chemistry MCQs
72. The heat energy produced when the human body metabolises 1 gram of fat is
A. 30 KJ
B. 1 KJ
C. 39 KJ
D. 29 KJ
✅ The correct answer is option C.
73. The main use of salt in the diet is to
A. make the taste of food better
B. produce in small amounts the hydrochloric acid required for the digestion of food
C. ease the process of cooking
D. increase the solubility of food particles in water
✅ The correct answer is option B.
74. The isomerism which exists between CH3CHCI2 and CH2CI. CH2CI is
A. chain isomerism
B. functional group isomerism
C. positional isomerism
D. metamerism
✅ The correct answer is option C.
75. The monomer of polythene is
A. vinyl chloride
B. ethylene
C. ethyl alcohol
D. None of the above
✅ The correct answer is option B.
76. The following are the half lives of four active isotopes. Which one of the following is the most dangerous to handle?
A. 3 billion years
B. 100 years
C. 0.01 minute
D. 13 days
✅ The correct answer is option C.
77. The high reactivity of fluorine is due to
A. its high electro negativity
B. small size of fluorine atom
C. availability of d-orbitals
D. strong F – F bond
✅ The correct answer is option A.
78. The octane number of zero is assigned to
A. 2-methyl octane
B. n-heptane
C. iso-octane
D. 3-methyl octane
✅ The correct answer is option B.
79. The main chemical constituent of clay is
A. silicon oxide
B. aluminium borosilicate
C. zeolites
D. aluminium silicate
✅ The correct answer is option D.