Commercial concentrated aqueous ammonia is 28% NH 3 by mass and has a density of 0.90 g/mL. What is the molarity of this solution?

Step 1: Understand the problem. We are asked to find the molarity of a solution. Molarity (M) is defined as the number of moles of solute per liter of solution. In this case, the solute is NH 3 and the solution is the aqueous ammonia.. Step 2: Calculate the mass of NH 3 in 1 mL of solution. Since the solution is 28% NH 3 by mass, this means that in every 100 g of solution, there are 28 g of NH 3 . Given the density of the solution is 0.90 g/mL, we can calculate the mass of NH 3 in 1 mL of solution by multiplying the density by the percentage of NH 3 .. Step 3: Convert the mass of NH 3 in 1 mL of solution to moles. We can do this by dividing the mass of NH 3 by its molar mass. The molar mass of NH 3 is approximately 17.03 g/mol.. Step 4: Convert the volume of the solution from mL to L. There are 1000 mL in 1 L, so we divide the volume in mL by 1000.. Step 5: Calculate the molarity of the solution. Now that we have the number of moles of NH 3 and the volume of the solution in L, we can calculate the molarity by dividing the number of moles by the volume in L.

Commercial concentrated aqueous ammonia is 28% NH 3 by mass and has a density of 0.90 g/mL. What is the molarity of this solution?

Hey everyone, we're told at 25 degrees Celsius a 32% by mass. Hydrochloric solution has a density of 1.161 g per mil. Leader Expresses concentration in molar itty first we need to recognize that 32% mass of hydrochloric solution essentially means that we have 32.0 g of hydrochloric acid In 100 g of solution. Since we have a total of 100%. So that means we have 100 g of our solution. Now to calculate our polarity, we need to calculate our moles of hydrochloric acid and our volume. So starting off with our moles of hydrochloric acid, we're going to take 32.0 g of hydrochloric acid And using dimensional analysis And our molar mass of hydrochloric acid, we know that we have 36.458g of hydrochloric acid, Her one mole of hydrochloric acid. So when we calculate this up, We end up with a value of 0. mol of hydrochloric acid. So now let's go ahead and calculate the volume of our solution. Starting off with 100 g of solution, We're going to use dimensional analysis again and we're going to take the density which is 1.161 g of solution per one millimeter. But since polarity is calculated in leaders, we have to convert our milliliters into leaders. So we have 10 to the third milliliters or one leader. So when we calculate this out, we end up with a volume of 0.0861 leaders. Now we can go ahead and calculate our polarity Again. Our polarity is going to be our moles of solute, which is 0.8777 mol of hydrochloric acid, divided by our leaders of solution, which is 0.0861 leaders. So when we calculate this out, we end up with a polarity of 10.2 molar, which is going to be our final answer. Now. I hope that made sense and let us know if you have any questions.

Ch.13 - Properties of Solutions

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Brown 14th Edition

Ch.13 - Properties of Solutions

Problem 56

Chapter 13, Problem 56

Commercial concentrated aqueous ammonia is 28% NH₃ by mass and has a density of 0.90 g/mL. What is the molarity of this solution?

Verified step by step guidance

Step 1: Understand the problem. We are asked to find the molarity of a solution. Molarity (M) is defined as the number of moles of solute per liter of solution. In this case, the solute is NH3 and the solution is the aqueous ammonia.

Step 2: Calculate the mass of NH3 in 1 mL of solution. Since the solution is 28% NH3 by mass, this means that in every 100 g of solution, there are 28 g of NH3. Given the density of the solution is 0.90 g/mL, we can calculate the mass of NH3 in 1 mL of solution by multiplying the density by the percentage of NH3.

Step 3: Convert the mass of NH3 in 1 mL of solution to moles. We can do this by dividing the mass of NH3 by its molar mass. The molar mass of NH3 is approximately 17.03 g/mol.

Step 4: Convert the volume of the solution from mL to L. There are 1000 mL in 1 L, so we divide the volume in mL by 1000.

Step 5: Calculate the molarity of the solution. Now that we have the number of moles of NH3 and the volume of the solution in L, we can calculate the molarity by dividing the number of moles by the volume in L.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Molarity

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in moles per liter (mol/L) and is crucial for understanding how much solute is present in a given volume of solution. To calculate molarity, one must know the amount of solute in moles and the total volume of the solution in liters.

Density

Density is the mass of a substance per unit volume, typically expressed in grams per milliliter (g/mL) or kilograms per cubic meter (kg/m³). In this context, the density of the ammonia solution allows us to convert the mass of the solution into volume, which is essential for calculating molarity. Understanding density helps in determining how much solution corresponds to a given mass.

Percent by Mass

Percent by mass is a way to express the concentration of a component in a mixture, calculated as the mass of the solute divided by the total mass of the solution, multiplied by 100. In this case, the 28% by mass of NH₃ indicates that there are 28 grams of ammonia in every 100 grams of solution. This information is vital for determining the amount of solute available for molarity calculations.