Mole Concept And Molar Masses

The mass of one mole of a substance in a gram is called its molar mass.

For instance, we can deduce a compound's formula by examining its composition, which is often expressed as the mass percentage of its constituent elements. Diverse methods exist for quantifying a property, such as heat capacity and specific heat capacity of a substance. Although these measurements pertain to the same attribute, they are distinct.

Similarly, there are various manners in which we express the mass of a substance, contingent on the amount under consideration. Here, we'll explore some frequently used expressions:

Atomic mass: This quantity pertains to the mass of a single atom of a substance. For instance, the atomic mass of hydrogen is 1.00784 atomic mass units (u).

Molecular mass: Specifically applicable to substances with diatomic molecules, like hydrogen gas, this signifies the mass of one molecule of the substance, amounting to 2.01568 u in the case of hydrogen.

Formula mass: Ionic compounds, devoid of molecules due to their composition of ions bonded by opposite charges, employ formula mass. In this context, formula units replace molecules, as exemplified by sodium chloride (NaCl) and potassium chloride (KCl).

Molar mass: This concept holds significant importance, extending beyond just chemistry to various other disciplines. It denotes the mass of one mole of a substance, expressed in grams per mole (g⋅mol−1). For instance, hydrogen's molar mass is 1.00784 g⋅mol−1.

In summary, the term "molar mass" designates the mass of one mole of a substance in grams. This particular expression encapsulates the fundamental idea of quantifying substance mass in relation to the mole concept.

Step 1: Calculate the molar mass of CaCO₃.
We are given:

• Ca = 40 μ
• C = 12 μ

We know that O = 16 μ.
Molar Mass of CaCO₃ = Ca + C + 3 × O
Molar Mass of CaCO₃ = 40 + 12 + 3 × 16 = 40 + 12 + 48 = 100 g/mol

Step 2: Convert ppm to mg/L.
We are given that 1 L CaCO₃ concentration = 1000 ppm.
1 ppm = 1 mg/L
Therefore, 1000 ppm = 1000 mg/L

Step 3: Convert mg/L to g/L.
1000 mg/L = 1 g/L.

Step 4: Convert g/L to mol/L
We have 1 g/L of CaCO₃.
Molar mass of CaCO₃ = 100 g/mol.
Concentration in mol/L = = mol/L = 10^-2 mol/L

Thus, the concentration of the solution in mol/L is 10^-2 mol/L

Step 1: Use Henry’s law. Henry’s law states: where is the concentration, is the pressure, and is the Henry’s law constant.

Step 2: Substitute the values.