how to calculate the weight of solute req'd to prepare 1 liter of 1 normal of:

a.) LiOH
b.) phosphoric acid
HELP.

To calculate the weight of solute required to prepare a solution of a given concentration, you need to know the molar mass of the solute and the desired concentration of the solution. I will guide you through the process step by step:

a) Calculating the weight of LiOH required to prepare 1 liter of 1 normal solution:

Step 1: Determine the molar mass of LiOH (Lithium hydroxide).

The molar mass of Li is approximately 6.941 g/mol, the molar mass of O is approximately 15.999 g/mol, and the molar mass of H is approximately 1.008 g/mol.

So, the molar mass of LiOH = (6.941 g/mol) + (15.999 g/mol) + (1.008 g/mol) = 23.948 g/mol.

Step 2: Calculate the weight of LiOH required.

The concept of normality, denoted by N, is a measure of the equivalent concentration of a solution. For a 1 normal solution, 1 equivalent of the solute is present in 1 liter of the solution.

For LiOH, the equivalent weight is equal to its molar mass since it produces one hydroxide ion (OH-) per molecule.

To calculate the weight of LiOH required, multiply the molar mass of LiOH by its equivalent weight and then multiply by the desired volume of the solution:

Weight of LiOH = (molar mass of LiOH) * (1 equivalent weight of LiOH) * (desired volume)

Weight of LiOH = 23.948 g/mol * 23.948 g/equivalent * 1 L = 23.948 g

Therefore, you would need 23.948 grams of LiOH to prepare 1 liter of 1 normal LiOH solution.

b) Calculating the weight of phosphoric acid (H3PO4) required to prepare 1 liter of 1 normal solution:

Step 1: Determine the molar mass of H3PO4 (phosphoric acid).

The molar mass of H3PO4 = (3 * 1.008 g/mol) + (1.008 g/mol) + (4 * 15.999 g/mol) = 97.995 g/mol.

Step 2: Calculate the weight of H3PO4 required.

Phosphoric acid (H3PO4) has three acidic hydrogen atoms, making it a triprotic acid. Each acidic hydrogen ionizes to form one equivalent of H+ ion.

For calculating the weight of phosphoric acid required to prepare a 1 normal solution, you multiply the molar mass of H3PO4 by 3 (to account for the three equivalents) and then multiply by the desired volume:

Weight of H3PO4 = (molar mass of H3PO4) * (3 equivalents of H3PO4) * (desired volume)

Weight of H3PO4 = 97.995 g/mol * 3 * 1 L = 293.985 g

Therefore, you would need 293.985 grams of phosphoric acid (H3PO4) to prepare 1 liter of 1 normal phosphoric acid solution.

Remember, it is essential to use the correct molar mass and understand the concept of normality in order to calculate the weight of solute required for a specific concentration.