The number of atoms in 560 g of Fe (atomic mass 56 g mol^–1) is:

1.	Twice that of 70 g N
2.	Half that of 20 g H
3.	Both 1 and 2
4.	None of the above

Which of the following concentration factor is affected by a change in temperature? 

1. Molarity 

2. Molality 

3. Mole fraction 

4. Weight fraction 

To neutralize 20 mL of 0.1 M aqueous solution of phosphorus acid \((H_3PO_3) \) completely, the volume of 0.1 M aqueous KOH solution required is:

\(6.02\times10^{20}\) molecules of urea are present in 100 mL of its solution. The concentration of urea solution is:
(Avogadro constant, \(N_A=6.02\times10^{23}~mol^{-1}\))

1. 0.001 M

2. 0.01 M

3. 0.02 M

4. 0.1 M

How many moles of magnesium phosphate, Mg₃(PO₄)₂, contain 0.25 moles of oxygen atoms?

Two solutions of a substance (non electrolyte) are mixed in the following manner.
480 mL of 1.5 M first solution +520 mL of 1.2 M second solution.
What is the molarity of the final mixture?

1. 2.70 M

2. 1.344 M

3. 1.50 M

4. 1.20 M