A pure substance or a homogeneous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases. When oil and water are combined, they do not mix evenly, but instead form two separate layers.
Answer:
B. n-octyl alcohol and 1-octene
Explanation:
Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. The principle is that different compounds in the sample mixture travel at different rates due to the differences in interactions with stationary phase and due to the differences in solubility in the solvent. The principal chemical property for separation using this technique is molecular polarity
You can intuit than hexadecane and octadecane don't have big polarity differences, also chlorobenzene and bromobenzene haven't.
An alcohol as n-octyl alcohol has different polarity than an alkene as 1-octene.
Thus, using thin layer chromatography is most easy to separate:
<em>B. n-octyl alcohol and 1-octene
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I hope it helps!
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<span>n this order, Ď=1.8gmL, cm=0.5, and mole fraction = 0.9
First, let's start with wt%, which is the symbol for weight percent. 98wt% means that for every 100g of solution, 98g represent sulphuric acid, H2SO4.
We know that 1dm3=1L, so H2SO4's molarity is
C=nV=18.0moles1.0L=18M
In order to determine sulphuric acid solution's density, we need to find its mass; H2SO4's molar mass is 98.0gmol, so
18.0moles1Lâ‹…98.0g1mole=1764g1L
Since we've determined that we have 1764g of H2SO4 in 1L, we'll use the wt% to determine the mass of the solution
98.0wt%=98g.H2SO4100.0g.solution=1764gmasssolution→
masssolution=1764gâ‹…100.0g98g=1800g
Therefore, 1L of 98wt% H2SO4 solution will have a density of
Ď=mV=1800g1.0â‹…103mL=1.8gmL
H2SO4's molality, which is defined as the number of moles of solute divided by the mass in kg of the solvent; assuming the solvent is water, this will turn out to be
cm=nH2SO4masssolvent=18moles(1800â’1764)â‹…10â’3kg=0.5m
Since mole fraction is defined as the number of moles of one substance divided by the total number of moles in the solution, and knowing the water's molar mass is 18gmol, we could determine that
100g.solutionâ‹…98g100gâ‹…1mole98g=1 mole H2SO4
100g.solutionâ‹…(100â’98)g100gâ‹…1mole18g=0.11 moles H2O
So, H2SO4's mole fraction is
molefractionH2SO4=11+0.11=0.9</span>
Answer:
1 M
Explanation:
Magnesium chloride will furnish chloride ions as:
Given :
Moles of magnesium chloride = 0.20 mol
Thus, moles of chlorine furnished by magnesium chloride is twice the moles of magnesium chloride as shown below:
Moles of chloride ions by magnesium chloride = 0.40 moles
Potassium chloride will furnish chloride ions as:
Given :
Moles of potassium chloride = 0.10 moles
Thus, moles of chlorine furnished by potassium chloride is same as the moles of potassium chloride as shown below:
Moles of chloride ions by potassium chloride = 0.10 moles
Total moles = 0.40 + 0.10 moles = 0.50 moles
Given, Volume = 500 mL = 0.5 L (1 mL = 10⁻³ L)
Concentration of chloride ions is:
<u>
The final concentration of chloride anion = 1 M</u>
Answer:
The density of O₂ gas is 1.71 
Explanation:
Density is a quantity that allows you to measure the amount of mass in a given volume of a substance. So density is defined as the quotient between the mass of a body and the volume it occupies:
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
So, you can get:
The relationship between number of moles and mass is:
Replacing:
So:
Knowing that 1 mol of O has 16 g, the molar mass of O₂ gas is 32 
.
Then:
In this case you know:
- P=1.27 atm
- molar mass of O₂= 32 .
- R= 0.0821
- T= 16 °C= 289 °K (0°C= 273°K)
Replacing:
Solving:
density= 1.71
<u><em>The density of O₂ gas is 1.71 </em></u><u><em></em></u>
