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

If the speed of light is 3.0 × 10⁸ m s^–1, then the distance covered by light in 2.00 nanoseconds will be:

1. 0.500 m

2. 0.600 m

3. 0.700 m

4. 0.800 m

In a reaction A + B₂ → AB_2, 
A will act as a limiting reagent if :

 
Choose the correct option:

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. 9

2. 8

3. 10

4. 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?

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

The mass of one ¹²C atom in g is:

1. 1.393 x 10^-23

2. 1.993 x 10^-23

3. 1.773 x 10^-23

4. 1.593 x 10^-23

Determine the number of significant figures that should be present in the final answers for each of the following expressions:

The molar mass of naturally occurring Argon isotopes is: