InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
The number of neutrons in deuterium, an isotope of hydrogen is: (A) one (B) two (C) three (D) None |
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Answer» The answer is (A) one |
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| 152. |
The mass number of an element is 7 and number of neutrons in its atom is 4. What is the number of electrons in the atom? (A) 3 (B) 4 (C) 7 (D) 11 |
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Answer» The answer is (A) 3 |
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| 153. |
What is molar mass? What are its units? |
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Answer» The mass of one mole of a substance is called its molar mass. Its unit is gram per mole (g/mol.) |
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| 154. |
The ion of an element has 3 unit positive charge. A mass number of its atom is 27 and number of neutrons in it is 14. What is the number of electrons in the ion? (A) 14(B) 13 (C) 27 (D) 10 |
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Answer» The answer is (D) 10 |
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| 155. |
How many moles of CO2 are there is 11g of carbon dioxide? Molar mass of CO2 is 44 g/mol. |
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Answer» n = \(\frac{m}{M}\) = \(\frac{11g}{44g/mol}\) = 0.25 mol |
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| 156. |
An isotope of an element having a number of neutrons 9 and its mass number is 17. Write the name and an atomic number of the element. |
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Answer» Mass number = Z + n 17 = Z + 9 Z = 17 – 9 Z = 8 Atomic number = 8 The name of the element is oxygen. |
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| 157. |
How many numbers of atoms of C is present in 1.5 moles of carbon? |
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Answer» 1 mole of C = 6.022 x 1023 atoms 1.5 mole of C = 6.022 x 102 x 1.5 = 9.033 x 1023 atoms of carbon. |
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| 158. |
Molar mass of HNO3 is 63 u, and an atomic mass of hydrogen and nitrogen are 1 u and 14 u respectively. Atomic mass of oxygen will be: (A) 3 u (B) 16 u (C) 48 u (D) 24 u |
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Answer» The answer is (C) 48 u |
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| 159. |
If atomic mass of nitrogen is 14 u and atomic mass of hydrogen is 1 u, what is the molar mass of ammonia? (A) 17 u (B) 15 u (C) 34 u (D) 30 u |
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Answer» The answer is (B) 15 u |
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| 160. |
Calculate the weight of nitrogen (in gms) at 22.4 liters at NTP. |
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Answer» At NTP, one mole of a gas occupies a volume of 22.4 liters. Since, N, molecules have molecular weight = 28 grams. Thus, 22.4 liters of N0 at NTP has weight = 28 grams. |
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