Question

If

the solubility of NaOH is 42 g/dL in cold water, What is the
normality of perfectly saturated solution.

Answer 1

The normality of a perfectly saturated solution of NaOH is 1.05 N.

Step-by-step explanation:

In this question, we are provided with the solubility of NaOH in cold water, which is 42 g/dL. The normality of a solution is a measure of its concentration and is defined as the number of equivalents of solute per liter of solution. To determine the normality of a perfectly saturated solution, we need to know the number of equivalents of NaOH that dissolve in one liter of water. To calculate this, we first need to convert the given solubility of NaOH to moles per liter. The molar mass of NaOH is 40 g/mol, so 42 g/dL can be converted to 1.05 mol/L. Since one mole of NaOH dissociates into one equivalent, the normality of the perfectly saturated solution is 1.05 N.

Answer 2

The normality of a saturated solution of NaOH with a solubility of 42 g/dL is 10.5 N, as calculated by converting the mass of NaOH to moles using its molar mass (40.0 g/mol) and considering the volume in liters.

Step-by-step explanation:

The student is asking about the calculation of the normality of a saturated solution of NaOH in water based on its solubility. Given that the solubility of NaOH is 42 g/dL in cold water, one needs to convert this mass to moles. The molar mass of NaOH is 40.0 g/mol. Therefore, 42 g of NaOH is equal to 1.05 moles (since 42 g × (1 mol / 40.0 g) = 1.05 mol). Normality (N) is calculated by multiplying the molarity by the equivalent factor, which for NaOH (a strong base that completely dissociates into one mole of sodium ions and one mole of hydroxide ions) is 1.

Therefore, the normality is the same as the molarity of the solution. Since the solubility is given in grams per deciliter, to find the normality, we first need to convert the volume to liters. A deciliter (dL) is one-tenth of a liter. Thus, 42 g/dL is equivalent to 420 g/L. This converts to 10.5 moles per liter, making the normality of the saturated NaOH solution 10.5 N.