Question

Construct a numerical problem to illustrate the size of avogadro's number. exchange problems with a classmate and then compare your answers.

Answer 1

In 30 grams of water there are 1.0036*10^24 molecules. Calculate Avogadro's number from these data.

Explanation:

The molar mass of water (H2O) is:

2*molar mass of H + molar mass of O

2*1 + 16 = 18 g/mol

This means that 1 mol has a mass of 18 grams. We know that the number of molecules present in 1 mol is the Avogadro's number. From data, we can state the following proportion:

30 g of H2O / 18 g of H2O = 1*10^24 molecules / x molecules

x = 1.0036*10^24*18/30 ≈ 6.022*10^23 molecules of H2O

This number of molecules corresponds to 1 mol, then it is the Avogadro's number.

Answer 2

Question made by me:

As you know that there are million of microbes in air.Consider a microbe have name Sekrit whose size is equal to
`1.023 * 10 ^ {-2}`. A scientist found the number of microbes on that tree equal to Avogadro's number which is
`6.023 * 10 ^(23)` on that particular kind of tree. Find the total mass of microbe Sekrit that exists on that particular tree.

Solution: Total mass of microbe Sekrit that exists on particular tree= Mass of a microbe Sekrit * Total number of microbe Sekrit on that particular tree

=
`1.023  * 10 ^(-2) * 6.023 * 10 ^(23)\\\\6.161529* 10^(21)`

Question Made by my friend:

A new kind of Star is found in the universe . The distance of that star from the planet earth is equal to Avogadro's number which is equal to
`6.023 * 10 ^(23)` . There are fifteen stars which form the pattern are equidistant from planet earth.Find the sum of total distances.

Solution: Distance of fifteen star from planet earth =
`6.023 * 10 ^(23)`

Total Distance =
`15 * 6.023 * 10^(23)=90.345 * 10^(23)=9.0345 * 10^(23)`

The two answers are different as it describes different kinds of problems using Avogadro's number.