Mole Concept And Molar Masses

The molar mass of Ni O is calculated by adding the molar masses of Ni and O. The percentage of Ni can be calculated by dividing the mass of Ni by the total mass and multiplying by 100. For Ni, with atomic mass 58.7, the mass of Ni in Ni is approximately 98 * 58.7, and the total mass is 98 * 58.7 + 100 * 16.

The mass percent of a substance is given by: - For urea: - For glucose: Thus, the mass percent of urea is 12% and glucose is 18%.

Step 1: Compute Initial Moles of H₂SO₄ Step 2: Convert Removed Molecules to Moles Step 3: Compute Remaining Moles Thus, the correct answer is .

The rms velocity of a gas is given by , where is the molar mass.
For O₂ (molar mass = 32 g mol^-1): .
For He (molar mass = 4 g mol^-1): .
Squaring both: , .
Taking the ratio: .
Thus, .

Option 1: 0.5 g atom of O = 0.5 mol of O atoms = 0.5 \times 16 = 8 g.
Option 2: 0.5 mol of O₃ (molar mass of O₃ = 48 g mol^-1) = 0.5 \times 48 = 24 g.
Option 3: 3 \times 10²² molecules of N₂ = ≈ 0.05 mol, mass = 0.05 \times 28 = 1.4 g.
Option 4: 5.6 L of CO₂ at STP (1 mol = 22.4 L) = = 0.25 mol, mass = 0.25 \times 44 = 11 g.
The highest mass is 24 g, which corresponds to option (2).