In experiment 9, in one operation, we heat up the alcohol with acid and do a concurrent distillation. What was the purpose of doing this
Answer:
we heat up because the component with lower boiling evaporates first,
leaving the other behind
Which choice is an element? Question 2 options: air (N2 mixed with O2 , and CO2 ) sodium chloride (NaCl) oxygen (O2 ) water (H2O )
Answer:
oxygen (O2 )
Explanation:
Select the container from the figure (Figure 1) that represents the dilution of a 4 % (m/v) KCl solution to each of the following: Figure1 of 1 There is a diagram showing several containers. One container is filled with 4 percent of mass to volume solution of NaCl. Container 1 is filled with a solution in which volume is two times less than the volume of NaCl solution. Container 2 is filled with a solution of a volume two times larger compared to the NaCl solution. Container 3 is filled with a solution of a volume two times larger than the volume of the solution in container 2. Part A 2 % (m/v) KCl
From the dilution formula, we have that at constant value of the solute, the volume of the solution is inversely proportional to the concentration.
The correct responses are;
Part A: Container 2Part B: Container 3Reasons:
The given parameters are;
The concentration of the KCl solution = 4% m/v
Taking the solution as solution of KCl
The volume of the solution in container 1 = Two times less than the volume of KCl solution.
[tex]V_{container \, 1} = \displaystyle \mathbf{ \frac{1}{2} \cdot V_{4\% \, solution}}[/tex]
The volume of the solution in container 2 = Two times larger compared to the volume of KCl solution.
[tex]V_{container \, 2} = \mathbf{\displaystyle 2 \times V_{4\% \, solution}}[/tex]
The volume of the solution in container 3 = Two times larger than the container two solution volume.
[tex]V_{container \, 3} = \displaystyle \mathbf{ 2 \times V_{container \, 2}}[/tex]
Therefore;
[tex]V_{container \, 3} = \displaystyle 2 \times 2 \times V_{4\% \, solution} = \mathbf{4 \times V_{4\% \, solution }}[/tex]
Part A Required:
a. To select the container that represent the dilution of the 4% solution to 2%
Solution:
The dilution formula is; C₁·V₁ = C₂·V₂
Therefore;
[tex]\displaystyle V_1 = \mathbf{\frac{C_1 \cdot V_1}{C_2}}[/tex]
C₁ =4%, C₂ = 2%, we get;
[tex]\displaystyle V_1 = \frac{4 \cdot V_1}{2} = 2 \cdot V_1[/tex]
The volume of the container that represents a 2% dilution is container 2
which is filled with a solution of a volume two times larger compared to the
KCl solution.
Part B:
Required:
The container diluted to a 1% m/v KCl solution.
Solution;
Using the dilution formula, we have;
C₁ = 4%, C₂ = 1%
Therefore;
[tex]\displaystyle V_1 = \frac{C_1 \cdot V_1}{C_2}[/tex]
[tex]\displaystyle V_1 = \frac{4 \cdot V_1}{1} = \mathbf{4 \cdot V_1}[/tex]
The volume of the solution is four times the volume of the 4% KCl solution, which is equivalent to the volume in container 3.
Possible parts of the question are;
Select the container that represents the dilution of the 4% (m/v) KCl solution to obtain the solutions that follows;
Part A: a 2% (m/v) KCl solution
Part B: a solution that is a 1% (m/v) KCl solution
Please see attached drawings
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4.What volume of hydrogen gas at STP is produced when 2.5 grams of zinc react with an
excess of hydrochloric acid?
Answer:
0.86
Explanation:
1mol of Zn has mass of 65.39g.The amount of Zn is 2.5g65.39g/mol=0.038mol.
The amount of H2 produced is the same as the amount of Zn consumed (0.038mol).
1mol of ideal gas will occupy 22.4L at STP.
The H2 will occupy 0.038mol×22.4L/mol=0.86L
.
7. What's the structure of methane, CH,? Is it polar or non-polar?
O A. Trigonal planar, polar
O B. Tetrahedral, polar
O C. Trigonal planar, non-polar
O D. Tetrahedral, non-polar
Answer:
The answer is D.
Explanation:
Methane (CH4) is a non-polar hydrocarbon molecule made of a single carbon atom and four hydrogen atoms. It is found in nature in the form of natural gas. It is non-polar because the difference in electronegativities between carbon and hydrogen is not sufficient to produce a polarized chemical connection between these two elements.
The methane molecule has a tetrahedral structure in terms of molecular geometry. Because the molecule is not planar, the angles between the H-C-H bonds are 109.5°, which is more than the 90° that they would be if the molecule were planar.
Explanation:
tetrahedral, non polar
Ionic compounds in own words
an ionic compound is made of two or more elements held by a strong electrostatic force. metal atoms lose electrons to become positive ions, and non metals gain electrons to become negative ions. ionic bonding occurs between metals and non metals
Plaseee ASAP
In an experiment hydrochloric acid is added drop by drop to solid sodium sulfite (Na2SO3). A gas is evolved and collected. Half of the collected gas is added to Lugol solution (I2 dissolved in KI solution), the other half of the gas is added to hydrogen sulfide solution. Write the equation of the reactions, discuss the observations that can be seen during the reactions and explain the changes. In your answer, also discuss the followings:
a) What gas is liberated during the reaction between HCl and Na2SO3? Why can it be liberated this way? Write an equation for the reaction.
b) What ability of the gas is
demonstrated in the reactions with Lugol solution and with H2S? Write equations and use oxidation numbers to prove it. What makes it possible for the substance to act differently in the two reactions?
c) What other properties of the gas evolved can you recall?
d) What are the environmental implications of the gas evolved? Write the appropriate equation for the reaction.
SO2 acts both as an oxidizing and a reducing agent depending on the conditions of the reaction. It also leads to acid rain.
The reaction of HCl with Na2SO3 occurs as follows;
Na2SO3 + 2HCl ------> 2NaCl + SO2 + H2O
The gas evolved in the reaction is SO2. It is liberated because sulfites react with acids to liberate sulfur IV oxide.
The ionic equation of the reaction is; [tex]SO3^2-(aq) + 2H^+(aq) ----> SO2(g) + H2O(l)[/tex]
The reaction of SO2 with Lugol solution occurs as follows;
SO2 +I2 + 2H20→ H2SO4 + 2HI. This demonstrates oxidation because sulfur is oxidized from +4 to +6 state from left to right. This shows SO2 as a reducing agent.
With H2S, the gas reacts as follows;
2H2S + SO2 → 3S (s) + 2H2O
The oxidation number of sulfur decreases from +4 to zero. This demonstrates the gas as an oxidizing agent. SO2 can act as oxidizing or reducing agent because it can change its oxidation state to +6(oxidation) by electron loss or gain electrons to decrease its oxidation state as low as -2.
The gas SO2 is an acid gas. It dissolves in water to yield an acid solution. Also SO2 is a bleaching agent. The major environmental impact of SO2 is that it leads to acid rain as follows; 2SO2 + O2 + 2H2O⇌2H2SO4.
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How could you tell if a substance has undergone a physical change or a chemical one?
Answer: Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.
A physical change is are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
No one helps me please find an answer to my recent question in chemistry...please!!!
oh so sad for ur msg
if i were science student then absolutely i will help
but i am। computer science student in management faculty so so sry
Explanation:
your answer to the chemistry question is given !
hope that helps you.
Are the 3 right for number 12?
Find five household items that contain ionic compounds. List the following information for each compound: a.name of the product
b. the chemical name of the ionic compound
d.the chemical formula of the ionic compound c. identify the ions present in each compound
Answer:
D . GOD BLESS .
Explanation:
What would the empirical formula be for the molecular compound CoH904?
Where did the atoms come from in the first place?
Answer:
All the carbon atoms in the human body were created in the stars. Elementary particles, such as protons, were formed during the "big bang"; that amazing moment about 14 billion years ago in which the universe got it's start.
Oil does not dissolve in water because
Explanation:
Oils are made up of long hydrocarbon chains which are non polar. Since water is a polar solvent oil doesn't dissolve in water well.( Polar solutes dissolve in polar solvents and non polar solutes dissolve in non polar solvents) The hydrocarbon chains are hydrophobic.
Which of the following types of models is generally used to predict long-term events? a. idea model b. physical model c. computer model d. none of the above Please select the best answer from the choices provided A B C D Mark this and return
Answer:
C
Computer model is generally used to predict long-term events
I hope it helps.
A car is traveling 70km in 45 minutes. How many miles an hour is the car traveling?
52
Explanation:
70x45÷60= 52
I hope this is helpful
What is the charge on ion X for Li2 X
Which which characteristics determines color? A. The Measurement from crest crest. B. The highest point on the wave. C. The lowest points on the waves D. The number of waves that pass per second. Please give me a good response.
Answer:
The answer is option A
Explanation:
This is because the measure from crest to crest is also known as the wavelength, and the color of a wave always depends on its wavelength, if you see the electromagnetic spectrum
Hope this helps!
pls help see attached pic for the question.
Answer: Evaporation and sublimation.
Explanation: Evaporation is the process of changing from liquid to gas, and sublimation is the process of changing from solid to gas.
pls help 8th grade k12
0 000
which explains why it is important to eat a full healthy meal before an oron o ping po
Food provides the carbon dioxide that is a product of cellular respiration
Food provides the oxygen that is a product of cellular respiration
Food provides the glucose that is a reactant in cellular respiration.
Food provides the energy that is a reactant in cellular respiration.
Answer:
A healthy diet is essential for good health and nutrition. It protects you against many chronic noncommunicable diseases, such as heart disease, diabetes and cancer. Eating a variety of foods and consuming less salt, sugars and saturated and industrially-produced trans-fats, are essential for healthy diet.
Did cellular respiration occur in trial 3 with the yeast and sugar?
PLEASE HELP ITS DO RIGHT NOWW
Answer:
In summary, yeast is a single-celled fungus that uses cellular respiration, which converts glucose and oxygen into carbon dioxide and ATP. ... Aerobic respiration makes the most ATP, between 36 and 38. Fermentation is anaerobic respiration and happens without oxygen.
Using the material selection processes, justify why the manufacturers/designers used the materials they did for super glue?
Answer:
Aluminium reusable water bottle Purpose of aluminum: Weighs less by volume than most other metals and comes at an affordable price.
Explanation:
Complete and balance the following redox reaction in basic solution
Cr2O7^2-(aq) + Hg(l) ----> Hg^2+(aq) + Cr^3+(aq)
Answer:
balanced in ACID not BASE
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
Answer
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
Explanation:
Cr2O7^2-(aq) + Hg(l) ----> Hg^2+(aqH) + Cr^3+(aq)
add H^1+ (acid) to capture the O and make 7 water molecules
Cr2O7^2-(aq) + Hg(l) + H^1+ ----> Hg^2+(aqH) + Cr^3+(aq) + 7H2O
Cr goes from +6 to +3 by gaining 3 e
Hg goes from 0 to +2 by losing 2 e
we need 3 Hg for every 2 Cr
so
Cr2O7^2-(aq) +3Hg(l) +14 H^1+ ----> 3Hg^2+ + 2Cr^3+(aq) + 7H2O
2 Cr on the right and left
Net 12 positive charges on the right and the left
3 Hg on the right and left
14 H on the right and left
the equation is balanced
we cannot balance the equation in a basic solution with OH^1-
we have plenty of O in the dichromate ion. we need to convert it to water which take free H^1+ from the acid
Mechanical waves travel fastest through
A -Solid
B -Liquid
C -Gas
D -Vacuum
Answer:
A-Solid
Explanation:
Waves travel faster in solids & slowest in gases
what is the expected hybridization of the central atom tetrahedral
Answer:
Tetrahedral molecules are normally spy hybridized.
Explanation:
How many federal agencies are responsible for managing land resources in the United States?
2
4
ОООО
6
10
The answer would be 4.
The agencies are:
Department of Agriculture's Forest Service (AFS)
Department of the Interior's Bureau of Land Management (BLM)
Fish and Wildlife Service (FWS)
National Park Service (NPS)
These four agencies cover around 95% of the land and are the only federal agencies.
I learned about these agencies in school.
Explain why caesium is more reactive than sodium.
You should answer in terms of electrons.
GIVING BRAINLY AND 20 POINTS
A sound wave in air has the wavelength of 1.36 m. Calculate its frequency? Assume the speed is 340 m/s.
Explanation:
frequency= velocity/ wavelength
= 340/1.36
=250
The table below shows the dimensions of two colored cubes.
Dimensions of Cubes
Cube Side (cm) Mass
(g)
Yellow 3 135
Black 2 48
Answer: The correct answer is black because the product of its side and mass is lower.
Explanation: The density of a substance is defined as the amount of matter that can be stored in a given volume.
Hence, the black cube will be denser because the product of its side and mass is lower.
Answer: it was wrong on my test
Explanation:
literally dont believe them
