If 3.01 × 10²⁰ molecules are removed from 98 mg of H₂SO₄, then number of moles of H₂SO₄ left are

• 0.1 × 10^-3 mol

• 9.95 × 10^-2 mol

• 0.5 × 10^-3 mol

• 1.66 × 10^-3 mol

One mole of CO₂ contains:

• 3g atoms of CO₂

• 18.1 × 10²³ molecules of CO₂

• 6.02 × 10²³ atoms of O

• 6.02 × 10²³ atoms of C

Equal moles of water and urea are taken in a flask. What is mass percentage of urea in the solution?

• 23.077%

• 230.77%

• 2.3077%

• 0.23077%

194.

Volume of water needed to mix with 10 mL N HCl to get 0.1 N HCl is:

• 900mL

• 9mL

• 90mL

• 100mL

The mass of 1 mole of electron is

• 9.1 × 10^-28 g

• 1.008 mg

• 0.55 mg

• 9.1 × 10^-27 g

What amount of bromine will be required to convert 2 g of phenol into 2, 4, 6-bribromo phenol?

• 20.44 gm

• 6.00 gm

• 4.00 gm

• 10.22 gm

The concentration of H₂O₂ solution of 10 volume is

• 30%

• 3%

• 1%

• 10%

One mole of magnesium nitride on the reaction with an excess of water gives

• one mole of NH₃

• two moles of NH₃

• one mole of HNO₃

• two moles of HNO₃

2.5 L of NaCl solution contain 5 moles of the solute. What is the molarity ?

• 5 M

• 2 M

• 2.5 M

• 12.5 M

In acidic medium, the equivalent weight of  K₂Cr₂O₇ ( Mol. wt. = M) is

• M

• M/2

• M/3

• M/6