Question

How many moles of water are present in 180 g of water
A . 1 mole
B . 18 mole
C . 10 mole
D . 100 mole

Answer 1

Hint: The concept of "moles" must be used in this question. The word "mole" can be used to describe how much substance is present. The Avogadro number is the molecular weight in grams for a molecule, and the molar mass of the material can be used to convert between moles and grams.

Complete answer:Let's start by discussing the Avogadro number and the concept of moles. The number of elementary particles, such as molecules, atoms, compounds, etc., per mole of a substance is known as Avogadro's number, and it is frequently represented by the symbol NA.
-Alternatively, the term "Avogadro's number" or "Avogadro's constant" refers to the quantity of units contained in one mole of any substance. Its value is 6.023×1023.
 The fact that the mass of a mole of a substance is equal to its molecular weight is another characteristic of Avogadro's number. Additionally, the mass of one mole of a compound is equal to its gram molecular mass, and the mass of one gram of an element is equal to its gram atomic mass.
\[Number\text{ }of\text{ }moles=\dfrac{given\text{ }mass}{molar\text{ }mass}=\dfrac{180g}{18g/mol}=10moles\]
Thus 18 g of water will contain one mole of water, that is 6.023×1023 molecules. 1o mole of water will contain 18×6.023×1023 molecules of water.

The correct answer is C.

Note: It should be noted that the definition of a mole can also include its volume. This means that one mole of any gas (6.023×1023 particles) will occupy a volume of 22.4 litres in a STP (standard pressure and temperature) atmosphere.