Calculate the molarity of the following aqueous solutions: (c) 25.0 mL of 3.50 M HNO3 diluted to 0.250 L.
Ch.13 - Properties of Solutions
Chapter 13, Problem 47
A sulfuric acid solution containing 571.6 g of H2SO4 per liter of solution has a density of 1.329 g/cm³. Calculate (d) the molarity of H2SO4 in this solution.

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Step 1: Calculate the molar mass of H2SO4. The molar mass is the sum of the atomic masses of all atoms in the molecule: 2 hydrogen atoms, 1 sulfur atom, and 4 oxygen atoms.
Step 2: Convert the mass of H2SO4 in grams to moles using the formula: moles = mass (g) / molar mass (g/mol). Use the given mass of 571.6 g of H2SO4.
Step 3: Determine the volume of the solution in liters. Since the density is given as 1.329 g/cm³, convert this to g/mL (which is the same numerically) and then use the fact that 1 L = 1000 mL to find the volume of 1 L of solution in grams.
Step 4: Calculate the mass of the solution using the density and the volume. Use the formula: mass = density × volume.
Step 5: Calculate the molarity of the solution using the formula: molarity (M) = moles of solute / liters of solution. Use the moles of H2SO4 from Step 2 and the volume of the solution in liters from Step 3.
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 grams and its molar mass.
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Density
Density is the mass of a substance per unit volume, typically expressed in grams per cubic centimeter (g/cm³) or kilograms per liter (kg/L). In this context, the density of the sulfuric acid solution allows us to convert the volume of the solution into mass, which is essential for determining the total amount of solute present in the solution.
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Molar Mass
Molar mass is the mass of one mole of a substance, usually expressed in grams per mole (g/mol). For sulfuric acid (H2SO4), the molar mass is calculated by summing the atomic masses of its constituent elements: hydrogen, sulfur, and oxygen. Knowing the molar mass is necessary to convert the mass of H2SO4 in the solution to moles, which is a key step in calculating molarity.
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Related Practice
Textbook Question
Textbook Question
What is the molarity of each of the following solutions: (b) 5.25 g of Mn(NO3)2⋅2H2O in 175 mL of solution,
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Textbook Question
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 °C. Calculate (a) the mass percentage,
Textbook Question
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 80.5 g of ascorbic acid dissolved in 210 g of water has a density of 1.22 g/mL at 55 °C. Calculate (c) the molality,
Textbook Question
The density of acetonitrile (CH3CN) is 0.786 g/mL and the density of methanol (CH3OH) is 0.791 g/mL. A solution is made by dissolving 22.5 mL of CH3OH in 98.7 mL of CH3CN. (a) What is the mole fraction of methanol in the solution?