Q. No.If the mass of air above a unit area at sea level is 1034 g cm⁻², what is the corresponding atmospheric pressure in pascal?
1. 1.01332 × 105 Pa
2. 1.01332 × 106 Pa
3. 1.01332 × 107 Pa
4. 1.01332 × 108 Pa
Which of the following is the SI unit of mass?
1. Kilogram (kg)
2. Gram (g)
3. Pascal (Pa)
4. Kilometres (km)
Which of the following correctly defines significant figures ?
| 1. | The total number of digits in a number, including the last digit that represents the uncertainty of the result. |
| 2. | The total number of digits in a number, excluding the last digit, which represents the uncertainty of the result. |
| 3. | The total number of digits in a number including the last digit that represents the certainty of the result. |
| 4. | The total number of last digits that represents the uncertainty of the result. |
The chloroform contamination level in water is 15 ppm (by mass of chloroform). Calculate the molality of chloroform in this water sample, which represents the number of moles of chloroform dissolved per kilogram of pure water solvent:
| 1. | 3.25 × 10-4
|
2. | 1.5 × 10-3
|
| 3. | 7.5 × 10-3
|
4. | 1.25 × 10-4 |
For the reaction:
A + B₂ → AB₂
Which of the following cases represent situations in which A acts as the limiting reagent?
| i. | 300 atoms of A reacts with 200 molecules of B |
| ii. | 2 moles A reacts with 3 moles B2 |
| iii. | 100 atoms of A reacts with 100 molecules of B |
| iv. | 5 moles A reacts with 2.5 moles B |
| v. | 2.5 moles A reacts with 5 moles B2 |
Choose the correct option:
| 1. | (i), (ii) | 2. | (i), (ii), (v) |
| 3. | (ii), (v) | 4. | All |
If 10 volumes of H₂ react completely with 5 volumes of O₂, what volume of water vapor will be produced under the same conditions of temperature and pressure?
1. Nine (9)
2. Eight (8)
3. Ten (10)
4. Eleven (11)
Find the value of 15.15 pm expressed in the basic SI unit of length.
1. 1.515 × 10–12
2. 2.57 × 10–11 m
3. 2.87 × 10–11 m
4. 1.515 × 10–11 m
Which will have the largest number of atoms among the following?
| 1. | 1 g Au (s)
|
2. | 1 g Na (s)
|
| 3. | 1 g Li (s)
|
4. | 1 g of Cl2(g) |
What would be the molarity of a solution of ethanol in water if the mole fraction of ethanol is 0.040?
(assume the density of water to be 1)
1. 3.143 M
2. 2.314 M
3. 2.413 M
4. 2.141 M
What is the mass, in grams, of one atom of carbon-12 (¹²C)?
1. 1.393 x 10-23
2. 1.993 x 10-23
3. 1.773 x 10-23
4. 1.593 x 10-23
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