how many grams of hydrogen peroxide (H2O2) must be added to 1500 ml of water to produce a concentration of 1.33 m (molal solution)
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To find the number of grams of hydrogen peroxide (H2O2) needed to produce a 1.33 m (molal) solution in 1500 ml of water, we need to follow these steps:
Step 1: Understand the given information
- Concentration (m) = 1.33 m
- Volume of water = 1500 ml
Step 2: Convert volume to grams
Since we have the volume in milliliters (ml), we need to convert it to grams. To do this, we need to know the density of water, which is approximately 1 g/ml. So, 1500 ml of water is equal to 1500 grams.
Step 3: Calculate the molality in moles of solute per kilogram of solvent
Molality (m) is defined as the number of moles of solute per kilogram of solvent.
Given that the concentration (m) is 1.33 m, the molality (m) can be calculated as follows:
m = moles of solute / kilograms of solvent
Since we have the volume of water in grams (1500 grams), we can convert it to kilograms by dividing it by 1000:
Kilograms of solvent = 1500 g / 1000 = 1.5 kg
Now we can calculate the moles of solute:
1.33 m = moles of solute / 1.5 kg
Moles of solute = 1.33 m * 1.5 kg
Step 4: Convert moles of solute to grams
To convert the moles of solute to grams, we need to know the molecular weight of hydrogen peroxide (H2O2). The molecular weight of H2O2 is approximately 34.01 g/mol.
So, we can calculate the grams of H2O2 needed as follows:
Grams of H2O2 = Moles of solute * Molecular weight of H2O2
Substituting the values:
Grams of H2O2 = (1.33 m * 1.5 kg) * 34.01 g/mol
Calculating this expression will yield the number of grams of hydrogen peroxide (H2O2) required to obtain a 1.33 m (molal) solution in 1500 ml of water.