1)How many mL of H2O2 are in 969 mL in solution ? * Given: 5.0% of H2O2 by volume.
2)What is the mole fraction of the solute in a 1.35m solution of CaCl2?
5% v/v solution means 5 mL H2O2 in 100 mL solution; therefore, in 969 mL solution there will be 5 x (969/100) =?? ml H2O2.
m = moles/kg solvent.
1.35 m means 1.35 moles CaCl2/kg solvent.
So you have 1.35 moles CaCl2.
Calculate moles water in 1 kg water.
mole fraction CaCl2 = moles CaCl2/total moles.
To find the answer to both questions, we need to understand some basic concepts and formulas.
1) How many mL of H2O2 are in 969 mL of solution? Given that the solution has 5.0% of H2O2 by volume.
To get the answer, we first need to calculate the volume of H2O2 present in the solution:
Step 1: Convert the percentage to a decimal by dividing it by 100.
5.0% = 5.0 / 100 = 0.05
Step 2: Multiply the percentage by the total volume of the solution.
0.05 x 969 mL = 48.45 mL
Therefore, there are 48.45 mL of H2O2 in a 969 mL solution.
2) What is the mole fraction of the solute in a 1.35m solution of CaCl2?
To find the mole fraction of the solute, we need to know the number of moles of the solute and the total number of moles in the solution.
Step 1: Determine the number of moles of CaCl2.
We have a 1.35m solution, which means that there are 1.35 moles of CaCl2 for every 1 liter (1000 mL) of solution.
To find the moles of CaCl2 in the given solution, we multiply the molarity (1.35 moles per liter) by the volume of the solution in liters. In this case, it is not provided, so we need additional information.
Let's assume that we are working with 100 mL of the solution.
Step 2: Convert the volume to liters.
100 mL = 100 mL / 1000 mL = 0.1 L
Step 3: Calculate the moles of CaCl2.
moles = molarity x volume
moles = 1.35 mol/L x 0.1 L = 0.135 moles
Step 4: Calculate the mole fraction.
The mole fraction of the solute (CaCl2) is given by the following formula:
Mole fraction = moles of solute / moles of solute + moles of solvent
In this case, we only have one solute (CaCl2). However, we need to know the moles of the solvent to calculate the mole fraction accurately.
Let's assume that the solvent is water (H2O), and we have 100 mL of the solution, with 0.135 moles of CaCl2 as determined earlier.
The molar mass of CaCl2 is approximately 110.98 g/mol.
The molar mass of H2O is approximately 18.015 g/mol.
Step 5: Convert the mass of CaCl2 to moles.
moles of CaCl2 = mass of CaCl2 / molar mass of CaCl2
Let's assume we have 10.0 g of CaCl2.
moles of CaCl2 = 10.0 g / 110.98 g/mol ≈ 0.090 moles
Step 6: Calculate the moles of the solvent (H2O).
moles of H2O = moles of solution - moles of solute
moles of H2O = 0.135 moles - 0.090 moles = 0.045 moles
Step 7: Calculate the mole fraction.
mole fraction of CaCl2 = moles of CaCl2 / (moles of CaCl2 + moles of H2O)
mole fraction of CaCl2 = 0.090 moles / (0.090 moles + 0.045 moles) ≈ 0.667
Therefore, the mole fraction of the solute (CaCl2) in a 1.35m solution is approximately 0.667.