Question

Find the Number of atom in given Sample.

a) 340g NH³
b) 440 Co²​

Answer 1

Answer:

The mass of NH3 is 34 g.

The molar mass is calculated by adding the atomic weight of the atoms and multiplying the number of atoms with it.

The mass of 1 mol (6.022×1023) of NH3 is calculated as shown below.

⇒ Mass of NH3= 14+3×1

⇒ Mass of NH3= 17 g.

The number of molecules is calculated by dividing mass by molecular mass multiplied by avagadro’s number.

The Avagadro’s number is the unit in one mole of any substance also stated as molecular weight in grams equal to 6.022×1023.

The number of molecules in 34 g NH3 is shown below.

⇒3417×6.022×1023

⇒12.044×1023

In NH3 molecule one nitrogen atom and three hydrogen atoms are present.

So in 1 mol of NH3 molecule, the total number of atoms present is 4.

⇒The number of atoms present in 34 g of NH3= 4×12.044×1023

⇒The number of atoms present in 34 g of NH3= 48×1023

Thus, the number of atoms present in 34 grams of NH3 is 48×1023.

So, the correct answer is Option D.

Answer 2

this is first Ans.

I know only this ans