Question

How is $1$ molar $NaOH$ different from $1$ molar $NaOH$ .

Answer 1

Molar and molar are two different things. The difference can be observed after the conversion of both quantities into the gram. So, first, we need to convert $1$ molar $NaOH$ into grams and then define $1$ molar $NaOH$ . After that compare both quantities to figure out the difference.

Complete answer:
First, we need to convert the $1$ mole $NaOH$ into grams –
The molar weight of sodium is $23g$ and the molar weight of oxygen is $16g$ whereas the molar weight of hydrogen is $1g$ . This makes the molar weight of sodium hydroxide - $16g + 23g + 1g = 40g$ which means that one mole of sodium hydroxide will contain $40g$ weight.
Now, we need to define the $1$ molar $NaOH$ –
The molar weight of sodium is $23g$ and the molar weight of oxygen is $16g$ whereas the molar weight of hydrogen is $1g$ . This makes the molar weight of sodium hydroxide - $16g + 23g + 1g = 40g$ which means that one mole of sodium hydroxide will contain $40g$ weight.
Now, this one mole or $40g$ of sodium hydroxide can be dissolved in $1000$ milliliters of water to obtain $1$ molar $NaOH$ solution.
Hence, we can conclude that $1$ mole $NaOH$ is the quantity of $40g$ of sodium hydroxide while $1$ molar $NaOH$ is the concentration in which $40g$ of sodium hydroxide will be dissolved in $1000$ milliliters of water. Simply, $1$ mole $NaOH$ is quantity and $1$ molar $NaOH$ is concentration.

Note:
The concentration of the solution can be expressed in many ways like molality, molarity, percent by mass or volume, part per million or billion, etc. $1$ molar solution means that it contains $1$ gram molar weight of solute dissolved in $1$ litre of the solvent. In simple words, the difference between mole and molar is that mole represents amount while molar represents concentration.