81. For a reaction
82. 100 mL of
A. an increase of 50 mL
B. an increase of 100 mL
C. an increase of 150 mL
D. a decrease of 50 mL
Answer : Option A
Explanation :
2 mL 3mL
83. An organic compound made of C, H, and N contains 20% nitrogen. Its molecular weight is (WB JEE 2009)
85. Calculate the number of moles in
A. 4.46
B. 44.6
C. 446
D. 4460
Answer : Option B
Explanation :
At STP, 22.4 L = 1 mol
86. An ore contains 1.24% of the mineral argentite
A. 23.15 g
B. 69.45 g
C. 92.6 g
D. 46.3 g
Answer : Option C
Explanation :
248 g 216 g
(?)
= 1.148 g
100 g 1.24 g
(?)
= 92.58 ≈ 92.6 g
87. Find the electric charge in coulomb of 9.0 gm of
A.
B.
C.
D.
Answer : Option A
Explanation :
No of moles of
88. Which of the following is not a homogeneous mixture ?
89. Which of the following has the largest number of atoms ?
A. 0.5 g atom of Cu
B. 0.635 g of Cu
C. 0.25 moles of Cu atom
D. 1 g of Cu
Answer : Option A
90. 27 g of Al (at mass = 27) will react with oxygen equal to (IIT 1978)