How many grams of glucose, C6H12O6, are required to prepare 100 mL of a 1.5 M solution?

Answer: To calculate the mass of glucose required to prepare 100 mL of a 1.5 M solution, you can follow these steps:

Step 1: Understand the concept of molarity. Molarity (M) is defined as the number of moles of a solute dissolved per liter of solution. The formula to calculate molarity is:

\[ M = \frac{\text{moles of solute}}{\text{liters of solution}} \]

Step 2: Calculate the moles of glucose required. We know the volume of the solution we want to prepare (0.1 L, since 100 mL is equivalent to 0.1 L) and the desired molarity (1.5 M). By rearranging the molarity formula, we can determine the moles of solute required:

\[ \text{moles of solute} = M \times \text{liters of solution} \] \[ \text{moles of glucose} = 1.5 \text{ M} \times 0.1 \text{ L} \] \[ \text{moles of glucose} = 0.15 \text{ moles} \]

Step 3: Calculate the molar mass of glucose. To convert moles to grams, you need to know the molar mass of the compound. The molar mass of glucose (C6H12O6) can be calculated by adding the atomic masses of each atom in the formula:

Carbon (C): 12.01 g/mol x 6 = 72.06 g/mol Hydrogen (H): 1.01 g/mol x 12 = 12.12 g/mol Oxygen (O): 16.00 g/mol x 6 = 96.00 g/mol

Total molar mass of glucose = 72.06 + 12.12 + 96.00 = 180.18 g/mol

Step 4: Convert moles of glucose to grams. Using the moles of glucose and its molar mass, you can calculate the required mass:

\[ \text{grams of glucose} = \text{moles of glucose} \times \text{molar mass of glucose} \] \[ \text{grams of glucose} = 0.15 \text{ moles} \times 180.18 \text{ g/mol} \] \[ \text{grams of glucose} = 27.027 \text{ grams} \]

Therefore, 27.027 grams of glucose are required to prepare 100 mL of a 1.5 M solution.

Extra: Glucose (C6H12O6) is a simple sugar that is an important energy source in living organisms and is a component of many carbohydrates. Preparing a solution involves dissolving a certain amount of solute (in this case, glucose) into a solvent to achieve the desired concentration.

When working with solutions, it is crucial to have a solid grasp of different ways to express concentration, with molarity being one of the most common ones in chemistry. Understanding molarity helps students to prepare solutions accurately for use in various experiments or procedures.

Furthermore, the concept of molar mass is essential because it links the microscopic world of atoms and molecules (measured in moles) to the macroscopic world (measured in grams) that we can manipulate in the laboratory.

In practical laboratory situations, one must also consider the purity of the solute and the precision of the measuring equipment. Always be aware of significant figures and the accuracy of your balance to ensure precise measurements.