Answer:
75 mg
Explanation:
We can write the extraction formula as
x = m/[1 + (1/K)(Vaq/Vo)], where
x = mass extracted
m = total mass of solute
K = distribution coefficient
Vo = volume of organic layer
Vaq = volume of aqueous layer
Data:
m = 75 mg
K = 1.8
Vo = 0.90 mL
Vaq = 1.00 mL
Calculations:
For each extraction,
1 + (1/K)(Vaq/Vo) = 1 + (1/1.8)(1.00/0.90) = 1 + 0.62 = 1.62
x = m/1.62 = 0.618m
So, 61.8 % of the solute is extracted in each step.
In other words, 38.2 % of the solute remains.
Let r = the amount remaining after n extractions. Then
r = m(0.382)^n.
If n = 7,
r = 75(0.382)^7 = 75 × 0.001 18 = 0.088 mg
m = 75 - 0.088 = 75 mg
After seven extractions, 75 mg (99.999 %) of the solute will be extracted.
<h3><u>Answer;</u></h3>
E. Horizon
<h3><u>Explanation;</u></h3>
A map is a symbolic representation of selected characteristics of a place or a given location. It present information about the world in a simple, visual way.
Several key features must be included on a map to aid the viewer in understanding the communication of a given map. They include;
- Legend; it serves as the decoder for the symbology in the data frame.
- Scale; explains the relationship of the date frame compared to the real world.
- Tittle; It instantly gives the viewer a succinct description of the subject matter of the map.
- Compass rose or North arrow
- Data frame, and
- Citation among others.
1. Heat always flow from a region of higher temperature
to a lower temperature, just like concentration gradient. So in this case,
since the metallic sphere is hotter than water, so naturally heat energy flows
from the metallic sphere to the water.
2. We use the formula:
Q = m C ∆T
where Q is the heat energy gained, m is mass of water, C
is heat capacity of water = 4.184 J/g°C and ΔT is change in temperature
Since density of water is 1 g/mL, so mass is also 100g,
therefore:
Q = 100 g * 4.184 J/g°C * (27.1°C - 25°C)
Q = 878.64 J
3. Heat gained by the water is equal to the heat lost by
the metal, therefore:
Q(water) = - Q(metal)
878.64 J = - 15 g * C * (27.1°C - 98°C)
C = 0.83 J/g°C
Answer:
8.9x10¹⁷ atoms of Al are present
Explanation:
To find the number of atoms from the mass of an atom we must convert, as first, the mass to moles using the molar mass of the atom (26.98g/mol For Aluminium).
Then, we must convert the moles to atoms knowing that 1mol = 6.022x10²³ atoms.
<em>Moles Aluminium:</em>
4.0x10⁻⁵g * (1mol / 26.98g) = 1.483x10⁻⁶ moles Al
<em>atoms:</em>
1.483x10⁻⁶ moles Al * (6.022x10²³ atoms / mol) =
<h3>8.9x10¹⁷ atoms of Al are present</h3>
The method that can be used to separate the mixture is chromatography.
<h3>
What is chromatography?</h3>
"Chromatography" is obtained form a Greek word which literarily means, color writing. It is a method of separation which is common in separating a mixture of pigments.
To obtain the colors used, two solvents are mixed and the sample ink is dissolved in the solvents then spotted on a thin layer and put into a TLC chamber then the chromatogram is allowed to develop.
The various components of the pigment will appear on the chromatogram and can be identified using spectrophotometry. The Rf values of each component can also be used to identify it.'
Learn more about chromatography: brainly.com/question/26491567