Question

Calculate the molar mass of water if it contains 50% heavy water (D2O).

Solution

Correct option is

19g mol–1

As water contains 50% D­2O, this means that it contains  mole of H2O and  mole of D2O.Mass of  mole of  Mass of . Hence, molar mass of the given sample of water = 9 + 10 = 19g mol–1

SIMILAR QUESTIONS

Q1

Calculate the mass of sodium acetate (CH3COONa) required to make500mL of 0.375 molar aqueous solution. Molar mass of sodium acetate is 82.0245 g mol–1

Q2

Calculate the concentration of nitric acid in moles per litre in a sample which has a density, 1.41 g ml–1and mass per cent of nitric acid in it being 69%.

Q3

How much copper can be obtained from 100 g of copper sulphate(CuSO4)? (Atomic mass of Cu =63.5amu) 

Q4

What is the concentration of sugar if its 20 g are dissolved in enough water to make a final volume up to 2 L?

Q5

If the density of methanol is 0.793 kg L–1, what is its volume needed for making 2.5 L of its 0.25 M solution?

Q6

What will be the mass of one12C atom in g?

Q7

What is the mass in grams of one molecule of caffeine (C8H10N4O2)?

Q8

What is the equivalent weight of KH(IO3)2 as an oxidant in presence of 4.0 (N) HCl when ICI becomes the reduced from?

Q9

 

An element X has the following isotopic composition:

                            200X : 90%

                            199X : 8.0%

                            202X : 2.0%

The weight average atomic mass of the naturally occurring element X is closest to :

Q10

 

 In the reaction,

      2 Al(s) + 6 HCl (aq) → 2 Al3+(aq) + 6 Cl (aq) + 3 H2 (g)