Entry Test (NMDCAT & ECAT) Preparation for FSc students to get admission to Medical colleges and Engineering Universities

MCQ-36
18.02g of H₂O sample has
A. 0.2 NA H-atoms
B. 0.1 NA O-atoms
C. 6.02 x 10²³ moles of H₂O
D. 6.02 x 10²³ molecules of H₂O

Answer: D

MCQ-37
Which of the following sample contain a maximum number of atoms?
A. 4g of H₂
B. 28g of N₂
C. 22.4 dm³ of CO₂ at STP
D. 1.5 mole of O₂

Answer: A

MCQ- 38
Consider the following reaction involved in the manufacturing of urea.
CO₂ + 2NH₃ —-> NH₂COONH₄
If 22g of carbon dioxide reacts with 34g of ammonia to form the ammonium carbamate, the reaction is taken as irreversible and goes to completion. Identify the limiting reagent and amount of ammonium carbamate formed.
A. CO₂, 78g
B. NH₃, 78g
C. CO₂, 39g
D. NH₃, 39g

Answer: C

MCQ-39
0.1 mole of Na₃PO₄ completely dissociates in water to produce Na⁺¹.
A. 6.02 x 10²²
B. 6.02 x 10²³
C. 1.806 x 10²³
D. 1.86 x 10²²

Answer: C

MCQ-40
A chemist is usually interested in
A. The rate of reaction
B. The mechanism of the reaction
C. The theoretical yield of the reaction
D. The efficiency of the reaction

Answer: D