Question

What is the mass of $4.75 \times {10^{21}}$ platinum atoms?

Answer 1

Hint : Mass of an object is the amount of matter in an object. Grams or kilograms are the most common units of mass. The amount of matter is measured by its mass, which is independent of its position in the universe and the gravitational force acting on it.


Complete Step By Step Answer:
Platinum is a chemical element with atomic number $78$ and the symbol $Pt$ . It's a silverish-white transition metal that's dense, malleable, ductile, and extremely unreactive. We know that the molar mass of platinum is $195.1$ grams per mole.
$6.023 \times {10^{23}}$ atoms of platinum constitute $1$ mole of platinum.
Therefore, by ratio and proportion, we can tell that,
$4.75 \times {10^{21}}$ atoms of platinum constitute $0.0078864$ moles of platinum.
We found the number of moles in $4.75 \times {10^{21}}$ atoms of platinum is equal to $0.0078864$
Now we shall calculate the mass of $4.75 \times {10^{21}}$ platinum atoms. The mass will be the product of the number of moles and the molar mass of platinum.
$
  m = n \times {M_r} \\
   = 0.0078864mol \times 195.1g.mo{l^{ - 1}} \\
   = 1.54g \\
 $

Therefore, the mass of $4.75 \times {10^{21}}$ atoms of platinum is equal to $1.54$ grams.

Additional Information:
 Platinum is most often used as a catalyst in chemical reactions, often in the form of platinum black. Its most common use is as a catalytic converter in vehicles. It allows for the complete combustion of low concentrations of unburned hydrocarbons from the exhaust into carbon dioxide and water vapor.

Note :
Platinum is one of the metals with the least amount of reactivity. It has exceptional corrosion resistance, even at high temperatures, and is thus classified as a noble metal. As a result, native platinum is often found chemically uncombined. As it appears naturally in the alluvial sands of numerous rivers; and it was first used to make artifacts by pre-Columbian South American natives.