The number of moles in 3.20 x 10² formula units of calcium iodide is 0.053 moles.
<h3>How to calculate number of moles?</h3>
The number of moles in the formula units of a substance is calculated by dividing the formula unit by Avogadro's number.
According to this question, 3.20 x 10² formula units are in calcium iodide. The number of moles is as follows:
no of moles = 3.20 x 10²² ÷ 6.02 × 10²³
no of moles = 0.53 × 10-¹
no of moles = 0.053 moles
Therefore, the number of moles in 3.20 x 10² formula units of calcium iodide is 0.053 moles.
Learn more about number of moles at: brainly.com/question/12513822
#SPJ6
B is the correct answer to your question
A gland is an organ that excretes chemical fluids to discharge into the surroundings or for use in the body.
The pH indicators to be used are Phenolphthalein, Red cabbage, Bromthymol blue and Congo red.
<h3>What are pH indicators?</h3>
Indicators are substances which change color as the pH of a medium changes.
The common indicators and their pH range is as follows:
- Phenolphthalein - pH range of 8.3 and 10.5
- Red cabbage - pH 2 to 10
- Bromthymol blue - 6.0 to 7.6
- Congo red - 3.0 to 5.2
Therefore, the indicators to be used are Phenolphthalein, Red cabbage, Bromthymol blue and Congo red.
Learn more about pH indicators at: brainly.com/question/13779537
#SPJ1
The mole fraction is calculated using the formula:
mole fraction of component A = # of moles of component A / # of total moles of the solution.
A) number of moles of ethanol
To calculate the number of moles of ethanol, you need its density, which will permit you to determine the mass of the 10.00 ml, and then convert into moles using the molar mass of ethanol.
The normal density of ethanol is 0.789 g/ml
density = mass / volume => mass = density * volume = 0.789 g/ml * 10.00 ml = 7.890 g
Molar mass of ethanol = 46.07 g/mol
number of moles = mass / molar mass = 7.890g / 46.07 g/mol = 0.1713 mol
B) number of moles of water
density of water = 1.00 g/mol
mass of water = density * volume = 1.00 g/mol * 2.00 ml = 2.00 g
number of moles of water = mass / molar mass = 2.00 g / 18.0 g/mol = 0.111 mol
C) mole fraction
mole fraction of ethanol = number of moles of ethanol / number of moles of solution
number of moles of ethanol = 0.1713 / (0.1713 + 0.111) = 0.1713 / 0.2824 = 0.607
Answer: 0.607
The volume of the final solution may be calculated by adding the volume of the two components. This is 10.00 ml of ethanol + 2.00 ml of water makes 12.00 ml of solution.
It is not clear what the second question is meant for. Some context is missing. If you know density and you know maqss (or can calculate the mass from other data) you do not need to measure the volume.
