Answer:
The unbalanced chemical equation is
K
2
Cr
2
O
7
+HCl→KCl+CrCl
3
+H
2
O+Cl
2
Balance all atoms except H and O.
K
2
Cr
2
O
7
+10HCl→2KCl+2CrCl
3
+H
2
O+Cl
2
Assign oxidation numbers.
K
2
+6
Cr
2
O
7
+10H
−1
Cl
→2KCl+2
+3
Cr
Cl
3
+H
2
O+
0
Cl
2
The oxidation number of Cr decreases from +6 to +3. Total decrease in the oxidation number of two Cr atoms is 6. The oxidation number of Cl increases from -1 to 0. Total increase in the oxidation number of 2 Cl atoms is 2.
Balance increase in oxidation number with decrease in oxidation number by using appropriate coefficients.
K
2
Cr
2
O
7
+14HCl→2KCl+2CrCl
3
+H
2
O+3Cl
2
Balance O atoms by adding six water molecules on products side.
K
2
Cr
2
O
7
+14HCl→2KCl+2CrCl
3
+7H
2
O+3Cl
2
H atoms are balanced.
K
2
Cr
2
O
7
+14HCl→2KCl+2CrCl
3
+7H
2
O+3Cl
2
This is balanced chemical equation.
The sum of the coefficients of the products is 2+2+7+3=14
a compound has a percent compostion of carbon equal to 48.8383%, hydrogen equal to 8.1636%, and oxygen equal to 43.1981%. what is the mepirical formula
Answer:
C₂H₃O
Explanation:
From the question given above, the following data were obtained:
Carbon (C) = 48.8383%
Hydrogen (H) = 8.1636%
Oxygen (O) = 43.1981%
Empirical formula =?
The empirical formula of the compound can be obtained as follow:
C = 48.8383%
H = 8.1636%
O = 43.1981%
Divide by their molar mass
C = 48.8383 / 12 = 4.07
H = 8.1636 / 1 = 8.1636
O = 43.1981 / 16 = 2.7
Divide by the smallest
C = 4.07 / 2.7 = 2
H = 8.1636 / 2.7 = 3
O = 2.7 /2.7 = 1
Thus, the empirical formula of the compound is C₂H₃O
The energy levels of hydrogenlike one-electron ions of atomic number Z differ from those of hydrogen by a factor of Z^2. Predict the wavelength of the 2s--->1s transition in He+.
Answer:
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Explanation:
For a hydrogen-like atom, the spectral line wavelength can be computed by using the formula:
[tex]\bar v = Z^2 R_H \Big(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}\Big)[/tex]
where:
emitted radiation of the wavenumber [tex]\bar v[/tex] = ???
atomic no of helium Z = 2
Rydberg's constant [tex]R_H = 1.097*10^7 \ m^{-1}[/tex]
the initial energy of the principal quantum [tex]n_1[/tex] = 2
the initial energy of the principal quantum [tex]n_1[/tex] = 2
Now, the emitted radiation of the wavenumber can be computed as:
[tex]\bar v = (2)^2 (1.097*10^7 \ m^{-1} ) \Big(\dfrac{1}{1^2}-\dfrac{1}{2^2}\Big)[/tex]
[tex]\bar v = 3.291 \times 10^ 7/m[/tex]
Now, the wavelength for the transition can be computed by using the relation between the wavelength λ and the emitted radiation of the wavenumber [tex]\bar v[/tex], which is:
[tex]\bar v = \dfrac{1}{\lambda}[/tex]
[tex]\lambda = \dfrac{1}{\bar v}[/tex]
[tex]\lambda = \dfrac{1}{3.291 \times 10^{7}}\times \dfrac{m}{1}[/tex]
[tex]\mathbf{\lambda =3.03859 \times 10^{-8} \ m}[/tex]
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Please help me, I don't bite. 3.
Answer:
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Explanation:
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Calculate the Experimental Molar Volume in L/mol of the Hydrogen gas, H2, if the volume of H2 at STP is 52.8 mL and the mass of Magnesium metal, Mg, used in the experiment is 0.055 g.
Answer:
The Experimental Molar Volume in L/mol of the Hydrogen gas=23.36L/mol
Explanation:
We are given that
Volume of H2 at STP=52.8mL
Mass of magnesium metal ,M(Mg)=0.055g
We have to find the Experimental Molar Volume in L/mol of the Hydrogen gas.
Molar mass of Mg=24.305 g/mol
Number of moles=[tex]\frac{given\;mass}{molar\;mass}[/tex]
Using the formula
Number of moles of Mg=[tex]\frac{0.055}{24.305}[/tex]moles
Number of moles of Mg=0.00226moles
Number of moles of Mg=Number of moles of H2
Number of moles of H2=0.00226moles
Molar volume of Hydrogen gas (H2)=[tex]\frac{volume\;at\;STP}{No\;of\;moles\;H_2}[/tex]
Molar volume of Hydrogen gas (H2)=[tex]\frac{52.8}{0.00226}mL/mol[/tex]
Molar volume of Hydrogen gas (H2)=[tex]\frac{52.8}{0.00226}\times 10^{-3}L/mol[/tex]
[tex]1L=1000mL[/tex]
Molar volume of Hydrogen gas (H2)=23.36L/mol
Hence, the Experimental Molar Volume in L/mol of the Hydrogen gas=23.36L/mol
Balance the following reactions and identify the species that have been oxidized and the species that have been reduced.
CL2 +I- -------------> I2 +CL-
WO2 + H2 ---------------> W + H2O
CA + H2O -----------------> H2 + CA(OH)2
AL+ O2 --------------------> AL2O3
Answer:
Balance the following reactions and identify the species that have been oxidized and the species that have been reduced.
CL2 +I- -------------> I2 +CL-
WO2 + H2 ---------------> W + H2O
CA + H2O -----------------> H2 + CA(OH)2
AL+ O2 --------------------> AL2O3
Explanation:
Oxidation is the process where an atom loses electrons.
During oxidation, the oxidation number of the atom increases.
Reduction is the process where an atom gains electrons.
During reduction, the oxidation number of the atom decreases.
The balanced chemical equations for the given reactions are shown below:
[tex]Cl_2 +2I^- -> I_2 + 2Cl^-[/tex]
Iodine undergoes oxidation and chlorine undergoes reduction.
[tex]WO_2 +2 H_2 -> W+ 2 H_2O\\[/tex]
In this reaction, W (tungsten) undergoes reduction and hydrogen undergoes oxidation.
[tex]Ca+2 H_2O ->H_2+Ca(OH)_2\\[/tex]
Ca undergoes oxidation and hydrogen undergoes reduction.
[tex]4Al+3O_2->2Al_2O_3\\[/tex]
Al undergoes oxidation and oxygen undergoes reduction.
g Consider two different liquids at atmospheric pressure: hexane and water. Hexane has a higher vapor pressure than water. As a result, the temperature at which hexane will boil will be [ Select ] water and its vapor pressure when it is boiling will be [ Select ] water when water is boiling.
Answer:
Lower than
Higher than
Explanation:
The vapour pressure and boiling point of liquids are inversely related. Thus, the higher the vapour pressure of a liquid, the lower it's boiling point. Lower vapour pressure implies that the liquid is easily converted into vapour phase.
If hexane has a higher vapour pressure than water then its boiling point is lower than that of water and its vapor pressure when it is boiling will be higher than water when water is boiling.
A 2,31M solution of trans-4-methyl-2-pentene (C6H12, 85mL) is combined with 7,5mL of 3,55M elemental bromine to form an addition product. With an expectation of 100% yield, more than 25mmols of elemental bromine would be consumed during this chemical process.
a. True
b. False
Answer:
The statement is false
Explanation:
Number of moles of alkene = 2.31 × 85/1000 = 0.196 moles
Number of moles of Br2 = 3.55 × 7.5/1000 = 0.0266 moles
Given that the reaction is 1:1
1 mole of alkene reacts with 1 mole of bromine
0.196 moles of alkene should react with 0.196 moles of bromine
Hence, to achieve 100%yield, 0.196 moles of bromine and not 25mmols of elemental bromine
b) What is the change in entropy of the reaction if ΔH° = -3.2 kJ mol-1?
every sperm has ____(one/two) sex chromosomes
PLEASE TELL THE ANSWER!!
Two chromosomes
Explanation:
The chromosomes are XY
Please mark me brainliest
Answer:
Two
Explanation:
Every sperm cell has two chromosomes.One is X and other is Y .They are found in pairs either XY or XXWhen Michelle's blood was testedthe chloride level was 0.45 g/dL. . What is this value in milliequivalents per liter? b. According to Table 9.6, is this value abovebelow within the normal range ?
Answer:
?what
Explanation:
i am having a hard time reading this
Which of the following represents a compound?
Na
CO2
Со
Mn
Answer:
CO2
Explanation:
Carbon dioxide is a chemical compound that consists of two oxygen atoms and one carbon atom
Which statement is true about how scientists draw conclusions from data?
A. Scientists do not allow others to make conclusions about their data.
B. Teams of scientists never share their data to help other teams draw conclusions.
C. Any two scientists will always come to the same conclusion about a data set.
D. Two scientists may have different underlying assumptions that lead them to different conclusions about the same data.
Answer:
D. Two scientists may have different underlying assumptions that lead them to different conclusions about the same thing.
Explanation:
It's all about how a person analyzes data. Some do it mathmatically while others do it logically. By doing it different ways, you may still come to the same conclusion, despite working at the problem in a different way.
The doctor has ordered Claforan 1 g in 100 ml D5W to run IV piggyback for 30 minutes twice daily. The pharmacy sends Claforn 2 g in a powdered form, which when reconstituted has a concentration of 180 mg Claforan per ml. How much Claforn will you add to the bag of D5W
Answer:
0.111 g
Explanation:
1 g = 1000 mg
Doctor ordered the following concentration of Claforan:
C = 1 g/100 mL x 1000 mg/1 g = 10 mg/mL
If we add 2 g iof Claforan, we obtain:
2 g Claforn ---- 180 mg/mL Claforan
To reach a concentration equal to C (10 mg/mL), we need:
10 mg/mL Claforan x 2 g Claforn/(180 mg/mL Claforan) = 0.111 g Claforn
Therefore, we have to add 0,111 g (111 mg) of Claforn to the bag of 100 ml D5W to obtain the ordered concentration of 10 mg/mL Claforan.
If the volume of the gas is increased to 9.6 L , what will the pressure be?
An ionic compound contains an unknown ion X and has the formula X3N2. Ion X contains 10 electrons. Write down the chemical symbol of X?
Answer:
Mg3N2
Explanation:
it would be magnesium as it would loss to electron so it would have 10 electron. you can see in the picture above .
hope this helps :)
D
Question 2
1 pts
How many moles of carbon tetrachloride are present in
18.Og of CC14?
i think .117018
now to get to the 20charaeactrs minimum.
The time required to pass one Faraday of electricity through a solution with a current of 0.3A is
Answer:
89.35 hour
Explanation:
Recall :
Charge on 1 electron = 1.6 × 10^-19 C
1 mole contains = 6.023 × 10^23
Therefore, the charge on 1 mole of electron will be :
Charge per electron × 1 mole :
(1.6 × 10^-19) * (6.023 * 10^23) = 96500 C = 1 Farad
1 Farad = 96500 C
Using the formula :
Q = Current(I) * time(t)
Q = I*t
t = Q/I
Current, I = 0.3 A
t = 96500 / 0.3
t = 321666.66 second
t = 321666.66 / 3600 = 89.35 hour
Glass tubes of the following diameters are arranged in a water trough. Rank the following glass tubes in decreasing order of their capillary rise.
Rank from highest to lowest capillary rise. To rank items as equivalent, overlap them.
1.25 mm, 1 mm, 0.75 mm, 0.25 mm, 0.50 mm
Answer:
0.25 mm> 0.50 mm > 0.75 mm> 1mm> 1.25 mm
Explanation:
Capillary movement involves the movement of liquid up through a capillary tube.
Looking at the question, we can see all the various diameters of the capillary tube are involved.
Note that, that the narrower the diameter of the capillary tube, the better the capillary action of the liquid (the liquid rises more now than then).
13. A mixture of MgCO3 and MgCO3.3H2O has a mass of 3.883 g. After heating to drive off all the water the mass is 2.927 g. What is the mass percent of
Answer:
63.05% of MgCO3.3H2O by mass
Explanation:
of MgCO3.3H2O in the mixture?
The difference in masses after heating the mixture = Mass of water. With the mass of water we can find its moles and the moles and mass of MgCO3.3H2O to find the mass percent as follows:
Mass water:
3.883g - 2.927g = 0.956g water
Moles water -18.01g/mol-
0.956g water * (1mol/18.01g) = 0.05308 moles H2O.
Moles MgCO3.3H2O:
0.05308 moles H2O * (1mol MgCO3.3H2O / 3mol H2O) =
0.01769 moles MgCO3.3H2O
Mass MgCO3.3H2O -Molar mass: 138.3597g/mol-
0.01769 moles MgCO3.3H2O * (138.3597g/mol) = 2.448g MgCO3.3H2O
Mass percent:
2.448g MgCO3.3H2O / 3.883g Mixture * 100 =
63.05% of MgCO3.3H2O by massWhat differences does distillation rely on to separate out parts of a solution?
O A. Different densities
O B. Different molecular masses
C. Different boiling points
O D. Different molecular sizes
Different boiling point.
Because in distillation the substance with lower boiling point is evaporated, leaving the other material(s).
Distillation relies on different boiling points to separate out parts of a solution.
the question is in the attachment
Answer:
About redox reaction which of the given statements are true?
Explanation:
Redox reaction is the one in which both oxidation and reduction reactions take place simultaneously.
For example:
[tex]C(s)+O_2(g)->CO_2(g)[/tex]
In this reaction, carbon undergoes oxidation and oxygen undergoes reduction simultaneously.
During this reaction, mutual exchange of electrosn take place between the oxidant and the reductant.
Among the given options,
Option B. electrons are transferred
and
option C.They include both oxidation and reduction takes place are the correct answers.
Please helpplease please..help
Answer:
vague symptoms are characteristic of an acute toxin, because of the of the lack of well defined consistency that these symptoms have in relation to the course of the disease progress.
The molar mass of a compound can be determined by the freezing point depression method. The solution must be relatively dilute and you must know the molal freezing point depression constant of the solvent, Kf. Which statement regarding Kf is true?
A. Kf should be small so that the solvent will not sublimate.
B. Kf will change depending on what solute is dissolved in the solvent.
C. Kf should be negative so the freezing point of the solution will decrease.
D. Kf should be large so the temperature change will be large enough to measure.
Answer:
K should be large so the temperature change will be large enough to measure.
Explanation:
Let us recall that;
∆T = k m I
Where;
∆T= change in boiling point
K= freezing point constant
m= molality
i= Van't Hoff factor
Since the change in temperature depends on k, the larger the value of k the larger the temperature change(Ts - Tb). Hence; K should be large so the temperature change will be large enough to measure.
Ts= freezing temperature of pure solvent
Tb= freezing temperature of solution
A dilute solution of an unknown ionic compound must be identified. Several experiments are run on solutions that contain the possible ions with the results tabulated below. Cation Addition of HCl Heated in hot water Ag+ White precipitate is formed No observable change Pb+2 White precipitate is formed Precipitate dissolves Zn+2 No observable change No observable change Anion Addition of Ca(NO3)2 Addition of HNO3 CO3–2 White precipitate is formed Precipitate dissolves and bubbles form PO4–3 White precipitate is formed Precipitate dissolves A white precipitate is formed when HCl is added to the unknown compound. When the white precipitate is heated in hot water, it does not dissolve. A white precipitate is formed when Ca(NO3)2 is added to the unknown compound. When HNO3 is added to the precipitate, it dissolves and bubbles are formed. What is the chemical formula of the unknown ionic compound?
Answer:
The chemical formula of the unknown ionic compound is Ag₂CO₃.
Explanation:
The method used to identify the ions present in a given solution of an unknown compound is known as qualitative analysis. Specific tests are carried based on the chemical reaction of these ions and the results they give in these reactions, the ions present innthe compound are identified. Some of the results or observations include formation of precipitates on addition of certain reagents, evolution of gases, colour changes, as well as the color changes that are observed in a flame test of a solutionmof these compounds.
In the given question, when testing for cations, a white precipitate is formed when HCl is added to the unknown compound. When the white precipitate is heated in hot water, it does not dissolve.
From the table of observations, both Ag+ and Pb²+ give a white precipitate on addition of HCl but Zn²+ does not. So the cation present is either Ag+ or Pb²+. However, when heated in hot water, the white precipitate does not dissolve as will be observed if Ag+ were the cation present. Thus, the cation is Ag+.
When testing for anions, a white precipitate is formed when Ca(NO3)2 is added to the unknown compound and when HNO3 is added to the precipitate, it dissolves and bubbles are formed.
Now comparing these results with that as observed with CO₃²- and PO₄³-, both form white precipitates on addition of Ca(NO₃)₂, and the precipitate dissolves on addition of HNO₃. However, only CO₃²- dissolves with the production of bubbles when HNO₃ is added. Thus, the anion is CO₃²-.
Therefore, the compound is Ag₂CO₃ which is formed from the cation Ag+ and CO₃²-.
Determine whether each phrase describes carboxylic acids or esters.
a. Usually have a sour odor _____________
b. Notable for their pleasant fragrances ___________
c. Do not form hydrogen bonds amongst themselves and have higher vapor pressure _____________
d. Their reactions with base are known as neutralizations ____________
e. Their reactions with base are known as saponifications _____________
When 2-methyl-3-hexene is treated with Cl2 in methanol, three products are formed (neglecting stereoisomers). Draw curved arrows to show the movement of electrons in this step of the reaction mechanism.
Answer:
Explanation:
The structural formula of 2-methyl-3-hexene is drawn in the attached image below. After then, the three possible structures were drawn and the mechanism reaction.
From the mechanism shown, methanol deprotonates methoxide proton and neutralizes the positive charge to form methoxide. This is followed by the movement of electrons that takes place from the region of higher electron density to lower electron density.
PLEASE HELP QUICKLY
The diagram shows the potential energy changes for a reaction pathway. (10 points)
Part 1: Does the diagram illustrate an endothermic or an exothermic reaction? Give reasons in support of your answer.
Part 2: Describe how you can determine the total change in enthalpy and activation energy from the diagram and if each is positive or negative.
The activation energy of the reaction is the difference between the highest point on the reaction profile and the energy of the reactants.
What is a potential energy diagram?A potential energy diagram or a reaction profile shows us the energ change between the reactants and the products.
As we look at the reaction profile, we observe that the products have a greater energy than the reactants hence the reaction is endothermic. The enthalpy chamgeis obtained by subtracting the energy of the products from the energy of the reactants.
The activation energy of the reaction is the difference between the highest point on the reaction profile and the energy of the reactants.
Learn more about energy profile: https://brainly.com/question/11256472
3. Does entropy increase or decrease in the following processes?
A. Complex carbohydrates are metabolized by the body, converted into simple sugars.
Answer: Increase
es-lesund
B. Steam condenses on a glass surface.
Answer:
decreare
-->
MgCl2(s)
C. Mg(s) + Cl2(g)
correct
Answer:
Answer:
HOPE IT helps much as you can
I need help with the practice question at the bottom. Thank you.
Explanation:
For this question, we apply the equation: Q = mCp AT Where m is the mass of the substance, Cp
is its specific heat capacity and AT is the
temperature change. Q = 896 x 0.45 x (5-94)
Q = -35884.8 Joules
So about -36 kilojoules of heat is released.
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determine the number of atoms of H in 35.0 grams of C2H4O2
Answer:
1.40x10^24 atoms of H
Explanation: