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How Many Molecules are Present in 9 g of Water

How Many Molecules are Present in 9 g of Water

Edited By Team Careers360 | Updated on Apr 10, 2023 05:42 PM IST

Introduction

Let's define a "molecule" before determining how many molecules are contained in the 9 grams of water. A molecule is a collection of two or more atoms that are chemically bound together and constitutes the smallest building block of a compound that can take part in a chemical reaction. Any compound's molecular weight must be multiplied by Avogadro's constant to determine its molecular composition.

Number of Molecules = number of moles X 6.023\times 10^{23} 1681128406242 …………(i)

Where the number of moles:

It is the proportion of a compound's actual mass to its molecular mass. The following is the expression to determine the number of moles:

n = \frac{m}{M}, 1681128406624 …………..(ii)

Here, "m" stands for the given mass of the compound, and "M" stands for the given compound's molar mass.

Calculation

Background wave

To find out the number of molecules in 9 grams of water:

Given the mass of water molecule = 9 g

The molecular mass of water molecule = 18 g

Using equation (ii), calculate the number of moles of water:

Number of moles, n = \frac{9}{18} 1681128406499 = 0.5

Using equation (i), calculate the number of molecules of water:

Number of molecules = n\times 6.023 \10^{23}

\Rightarrow 0.5 \times 6.023 \10^{23}

\Rightarrow 3.01 \times 10^{23}

1681128406754

Conclusion

Hence, the number of molecules in 9 grams of water is 3.01 \times 10^{23} 1681128406384molecules.

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