Question

The volume of water to be added to convert $10$ ml of deca molar $HCl$ solution to deci molar solution is: -
 (A). $99$ ml
(B). $100$ml
(C). $1000$ ml
(D). $990$ ml

Answer 1

Hint: Volume is the net quantity to be filled inside a container. The expression of concentration of solution is mostly represented in molarity which is defined as the number of solutes dissolved per liter of the given solution. Whereas the term deca or deci are the measuring unit of the length or time or the concentrations.

Complete answer:

The Metric System
Prefix	Symbol	Exponential
Yotta	Y	${10^{24}}$
Zetta	Z	${10^{21}}$
Exa	E	${10^{18}}$
Peta	P	${10^{15}}$
Tera	T	${10^{12}}$
Giga	G	${10^9}$
Mega	M	${10^6}$
Kilo	K	${10^3}$
Hecto	h	${10^2}$.
Da	da	${10^1}$
Gram/Meter/Sec	g/m/sec	${10^0}$
Deci	d	${10^{ - 1}}$
Centi	c	${10^{ - 2}}$
Milli	m	${10^{ - 3}}$
Micro	$\mu $	${10^{ - 6}}$
Nano	n	${10^{ - 9}}$
Pico	p	${10^{ - 12}}$
Femto	f	${10^{ - 15}}$
Atto	a	${10^{ - 18}}$
Zepto	z	${10^{ - 21}}$
Yocto	y	${10^{ - 24}}$

The molarity of a solution is also defined as the ratio of the number of moles of solute to volume of the solution in liters. Iff molarity of two solvents is given and we need to calculate the volume used then we can use the formula of the molarity equation which is as follows ${M_1}{V_1} = {M_2}{V_2}$ .
Thus, using the formula: -
${M_1}{V_1} = {M_2}{V_2}$
Now substituting the given values,
$10 \times 10 = 0.1 \times V$
Thus $V = 1000$ ml
As the $10$ ml of water is to be added then the net $HCl$ required is $1000 - 10 = 990$ ml.

Note:
The molarity equation is a basic generalized equation in which the molarity iff replaced by normality will give a normality equation, whereas iff replaced by molality then will give a molality equation and iff replaced by formality then will give a formality equation. The calculative units of molarity is molar, molality is molal and normality is normal.