You must add 68 g H_2O_2 to 1500 mL water.
Step 1. Calculate the mass of water
Mass of water = 1500 mL × 1.0 g/1 mL 1500 g = 1.50 kg
Step 2. Calculate the moles of H_2O_2.
Moles of H_2O_2 = 1.500 kg water × 1.33 mol H_2O_2/1 kg water
= 2.00 mol H_2O_2
Step 3. Calculate the mass of H_2O_2
Mass of H_2O_2 = 2.00 mol H_2O_2 × 34.01 g H_2O_2/1 mol H_2O_2
= 68 g H_2O_2
Answer : The correct option is, 68 g
Explanation :
First we have top calculate the mass of solvent (water).
Formula used :
[tex]Density=\frac{Mass}{Volume}[/tex]
Now put all the values in this formula, we get the mass of solvent (water).
[tex]1.0g/ml=\frac{Mass}{1500ml}[/tex]
[tex]\text{Mass of water}=1500g[/tex]
Now we have to calculate the mass of hydrogen peroxide.
Molality : It is defined as the number of moles of solute present in one kilogram of solvent.
In this question, the solute is hydrogen peroxide.
Formula used :
[tex]Molality=\frac{w_b}{M_b\times w_a}\times 1000[/tex]
where,
Molality = 1.33 mole/Kg
[tex]w_a[/tex] = mass of solvent (water) = 1500 g
[tex]w_b[/tex] = mass of solute hydrogen peroxide = ?
[tex]M_b[/tex] = molar mass of solute hydrogen peroxide = 34 g/mole
Now put all the given values in the above formula, we get the mass of hydrogen peroxide.
[tex]1.33mole/Kg=\frac{w_b}{34g/mole\times 1500g}\times 1000[/tex]
[tex]w_b=67.83g=68g[/tex]
Therefore, the grams of hydrogen peroxide will be, 68 grams.
