Chapter 12, Problem 12.160MP

Interpretation Introduction

(a)

Interpretation:

Number of moles of ${\text{H}}_{\text{2}}$ gas evolved should be determined.

Concept introduction:

• Ideal gas equation: Ideal gas equation is a relation between four variables and it describes the state of any gas
From Boyle’s Law we get, $\text{Vα}\frac{\text{1}}{\text{P}}$

From Charles’ Law we get, $\text{VαT}$

From Avogadro’s Law we get, $\text{Vαn}$

Now combining these three laws we get the ideal gas equation which is as follows:-

  $\begin{array}{l}\text{Vα}\frac{\text{nT}}{\text{P}}\\ \text{V=}\frac{\text{nRT}}{\text{P}}\\ \text{PV=nRT}\end{array}$

Where
R is the universal gas constant = $\text{0}\text{.082057 Latm/K/mol}$

n is the number of moles
P is the pressure
V is the volume
T is the temperature

Interpretation Introduction

(b)

Interpretation:

The mass of ${\text{MCl}}_{\text{x}}$ formed should be determined

Concept Introduction:

• Stoichiometry concerns itself with the weight relations of elements in chemical reaction. Thus, in stoichiometric calculations we come across chemical formula and chemical equation.
• The relation between molar mass, mass and number of moles is
Mass = Molar mass × Number of moles

(c)

Interpretation Introduction

Interpretation:

The molality of the particles in the solution of ${\mathrm{MCl}}_x$ should be determined

Concept introduction:

• Molality: The number of moles of solute dissolved per kilogram of solvent is called molality
• Depression in freezing point: The freezing point of a solution containing non-volatile solute is lower than freezing point of pure solvent. That decrease in freezing point of solution in comparison to pure solvent is called depression in freezing point.
• Molal depression constant k_f : When the molality of the solution is one then depression in freezing point is called molal depression constant.
• The relation between molality , depression in freezing point and molal depression constant is ${\text{ΔT}}_{\text{f}}{\text{=m×k}}_{\text{f}}$

(d)

Interpretation Introduction

Interpretation:

Moles of ions present in the solution should be determined

Concept introduction:

• Molality : The number of moles of solute dissolved per kilogram of solvent is called its molality

  $\text{molality=}\frac{\text{Number}\text{of}\text{moles}\text{of}\text{particles}}{\text{Mass}\text{of}\text{water}\left(\text{in}\text{g}\right)}\text{×1000}$

(e)

Interpretation Introduction

Interpretation:

The formula and molecular weight of ${\text{MCl}}_{\text{x}}$ should be determined

Concept introduction:

• Molar ratio : It is the ratio between the number of moles of element present in the compound
• Molar mass: It can be represented by adding the atomic mass of all the element present in the compound
• The relation between mass ,number of moles and molar mass of the compound is
    $\text{Number}\text{of}\text{moles=}\frac{\text{Given}\text{mass}}{\text{Molar}\text{mass}}$

(f)

Interpretation Introduction

Interpretation:

The metal M should be identified.

Concept introduction:

• The relation between mass, molar mass and number of moles is

$\mathrm{Number}ofmoles=\frac{Givenmass}{Molarmass}$