Railway Science (Chemistry-Solutions)

Total Questions: 42

41. In a water molecule, the ratio of mass of Hydrogen to the mass of Oxygen is always: [RRB ALP Tier - I (21/08/2018) Morning]

Correct Answer: (a) 1 : 8
Solution:

42. The amount of glucose required to prepare 250g of a 5% solution of glucose by mass is : [RRB ALP Tier - I (29/08/2018) Morning]

Correct Answer: (b) 12.5g
Solution:

Mass by mass percentage or (m/m%) is a measure of the concentration of a solution. It is expressed in terms of the mass of the solute relative to the mass of the solution.
m/m% = (mass of solute/mass of solution) × 100
given,
mass of solution = 250g
solution of glucose by mass = 250 × 5/100 = 12.5 g.