Ammonia, methane, and phosphorus trihydride are three different compounds with three different boiling points. Rank their boiling points in order from lowest to highest.
A. CH4< NH3 < PH3
B. NH3 < PH3< CH4
C. CH4 < PH3 < NH3
D. NH3 < CH4< PH3
E. PH3< NH3 < CH4

Answers

Answer 1

Answer:

B. NH3 < PH3< CH4

Explanation:

Hello,

In this case, taking into account that the boiling point of ammonia, methane and phosphorous trihydrate are -33.34 °C , -161.5 °C  and -87.7 °C , clearly, methane has the lowest boiling point (most negative) and ammonia the greatest boiling point (least negative), therefore, ranking is:

B. NH3 < PH3< CH4

Best regards.


Related Questions

What would happen to the measured cell potentials if 30 mL solution was used in each half-cell instead of 25 mL

Answers

Answer:

The answer is "[tex]\bold{\log \frac{[0] mole}{[R]mole}}[/tex]"

Explanation:

[tex]E_{cell} =E_{cell}^{\circ} - \frac{0.0591}{n}= \log\frac{[0]}{[R]}\\[/tex]

In the above-given equation, we can see from [tex]E_{ceu}[/tex], of both oxidant [tex]conc^n[/tex]as well as the reactant were connected. however, weight decreases oxidant and reduction component concentration only with volume and the both of the half cells by the very same factor  and each other suspend

[tex]\to \log \frac{\frac{\text{oxidating moles}}{25 \ ml}}{\frac{\text{moles of reduction}}{25 ml}} \ \ = \ \ \log \frac{\frac{\text{oxidating moles}}{30 \ ml}}{\frac{\text{moles of reduction}}{30 ml}} \\\\\\[/tex]

[tex]\to {\log \frac{[0] mole}{[R]mole}}[/tex]

The cell potential of the electrochemical reaction has been the same when the volume has been reduced from 30 mL to 25 mL in each half cells.

The cell potential has been given as the difference in the potential of the two half cells in the electrochemical reaction.

The two cells has been set with the concentration of solutions in the oxidation and reduction half cells.

Cell potential change

The cell potential has been changed when there has been a change in the potential of the half cells.

The volume of 30 mL to the solution has been, resulting in the cell potential difference of x.

With the volume of 25 mL, there has been the difference in the potential being similar to the 30 mL solution, i.e. x.

Thus, the cell potential of the electrochemical reaction has been the same when the volume has been reduced from 30 mL to 25 mL in each half cells.

Learn more about cell potential, here:

https://brainly.com/question/1313684

Which led to the formation of oceans after water on Earth's surface evaporated?

Answers

Answer:

condensation

Explanation:

What led to the formation of oceans after the water on the Earth's surface evaporated is a condensation reaction of water vapour.

The water present on the surface of the earth was able to evaporate as a result of the hot condition of the primitive earth. As the earth cools down the water vapour present in the atmosphere began to condense, gradually forming puddles of water and eventually leading to the formation of various oceans as we currently have it on the earth.

Answer:

as earth cooled, water in the atmosphere condensed.

Explanation:

An atom of 122In has a mass of 121.910280 amu. Calculate the binding energy in MeV per NUCLEON. Use the masses: mass of 1H atom

Answers

The given question is incomplete, the complete question is:

An atom of 122In has a mass of 121.910280 amu. Calculate the binding energy in MeV per atom. Use the masses: mass of 1H atom = 1.007825 amu mass of a neutron = 1.008665 amu 1 amu = 931.5 MeV

Answer:

The correct answer is 1029.95 MeV.

Explanation:

Based on the given information,  

The mass of proton is 1.007825, the mass of neutron is 1.008665.  

The atomic number of Indium is 49, therefore, the number of neutrons will be, 122-49 = 73.  

Now the calculated mass will be,  

= 49 * 1.007825 + 73 * 1.008665

= 49.383425 + 73.632545

= 123.01597

The mass defect is calculated by subtracting the actual mas from calculated mass,  

Mass defect = Actual mass - Calculated mass

= 121.910280 - 123.01597

= -1.10569 amu

Now the binding energy will be,  

Binding energy = 1.10569 * 931.5 MeV

= 1029.95 MeV

A piece of solid metal is put into an aqueous solution of . Write the net ionic equation for any single-replacement redox reaction. Assume that the oxidation state of in the resulting solution is 2 .

Answers

The question is incomplete,the complete question is as follows:

A piece of solid Fe metal is put into an aqueous solution of Cu(NO3)2. Write the net ionic equation for any single-replacement redox reaction that may be predicted. Assume that the oxidation state of in the resulted solution is 2 . (Use the lowest possible coefficients for the reaction. Use the pull-down boxes to specify states such as (aq) or (s). If a box is not needed, leave it blank. If no reaction occurs, leave all boxes blank and click on Submit.)

Answer:

Fe(s) + Cu^2+(aq) => Fe^2+(aq) + Cu(s)

Explanation:

An ionic equation is a chemical equation which shows clear image of reactions of the electrolytes in aqueous solution.

Molecular reaction equation for the reaction between iron and copper II nitrate is as follows:

Fe(s) + Cu(NO3)2(aq) => Fe(NO3)2(aq) +Cu(s)

The net ionic equation for any single-replacement redox reaction is as follows:

Fe(s) + Cu^2+(aq) => Fe^2+(aq) + Cu(s)

What are the conjugate acid-base pairs in the following chemical reaction? HBr(aq)+ CH3COOH(aq) ⇌ CH3C(OH)2+(aq) + Br-(aq)

Answers

Answer:

HBr, CH3C(OH)2 and CH3COOH, Br-

Explanation:

The conjugate acid-base pairs acid reacts with base to form a conjugate acid and conjugate base.

Conjugate acid is formed when a bases receives a proton  (H+) and a conjugate base is formed when an acid losses a proton (H+).

From the given equation:

HBr, CH3C(OH)2 and CH3COOH, Br- are conjugate acid-base pair, where HBr is an acid and CH3C(OH)2 is a conjugate acid while CH3COOH and Br- is the conjugate base.

Sulfur dioxide reacts with oxygen to form sulfur trioxide. What change in hybridization of the sulfur occurs in this reaction ? g

Answers

Answer:

PLEASE LOOK INN TO THE FILE YOU WILL GET ANSWER AND ALSO SUMMARY THANKS FOR ASKING QUESTION.

Explanation:

According to the following reaction, how many moles of ammonia will be formed upon the complete reaction of 31.2 grams of nitrogen gas with excess hydrogen gas ? nitrogen(g) + hydrogen(g) ammonia(g)

Answers

Answer:

4.46 mol of NH3

Explanation:

The equation of he reaction is given as;

2N + 3H2 --> 2NH3

From the stochiometry of the reaction, 1 mol of Nitrogen produces 2 mol of Ammonia.

Mass of Nitrogen = 31.2g

Molar mass of Nitrogen = 14g/mol

Number of moles = Mass / Molar mass = 31.2 / 14 = 2.23 mol

Since 1 mol of N = 2 mol of NH3;

2.23 mol of N2 would produce x

x = 2.23 * 2 = 4.46 mol of NH3

Calculate the molality of a solution containing 141.5 g of glycine (NH2CH2COOH) dissolved in 4.456 kg of H2O

Answers

Answer:

0.423 m.

Explanation:

The following data were obtained from the question:

Mass of glycine (NH2CH2COOH) = 141.5 g

Mass of water = 4.456 kg

Molality =.?

Next, we shall determine the number of mole in 141.5 g of glycine (NH2CH2COOH.

This is illustrated below:

Mass of glycine (NH2CH2COOH) = 141.5 g

Molar mass of glycine (NH2CH2COOH) = 14 + (2x1) + 12 + (2x1) + 12 + 16 + 16 + 1 = 75 g/mol

Mole of glycine (NH2CH2COOH) =.?

Mole = mass /Molar mass

Mole of glycine (NH2CH2COOH) = 141.5/75

Mole of glycine (NH2CH2COOH) = 1.887 moles

Finally, we shall determine the molality of the solution as follow:

Molality is simply defined as the mole of solute per kilogram of water. Mathematically it is expressed as:

Molality = mole / mass (kg) of water

With the above formula, we can obtain the molality of the solution as follow:

Mole of glycine (NH2CH2COOH) = 1.887 moles

Mass of water = 4.456 kg

Molality =.?

Molality = mole /mass (kg) of water

Molality =1.887/4.456

Molality = 0.423 m

Therefore, the molality of the solution is 0.423 m

Which of the following is required for the flow of current in all systems?
a) the presence of ions
b) an electrical potential ofo
c) a closed circuit
d) a short circuit

Answers

Answer:

I would say c) a closed circuit.

Hope I was right.

At a constant temperature, a sample of a gas in a balloon that originally had a volume of 5.00 L and pressure of 626 torr has its volume changed to 6.72 L. Calculate the new pressure in torr.

Answers

Answer:

466 torr

Explanation:

Step 1: Given data

Initial pressure (P₁): 626 torrInitial volume (V₁): 5.00 LFinal pressure (P₂): ?Final volume (V₂): 6.72 LConstant temperature

Step 2: Calculate the final pressure

Since we have a gas changing at a constant temperature, we can calculate the final pressure using Boyle's law.

P₁ × V₁ = P₂ × V₂

P₂ = P₁ × V₁ / V₂

P₂ = 626 torr × 5.00 L / 6.72 L

P₂ = 466 torr

At 2000°C the equilibrium constant for the reaction 9_1.gif is 9_2.gif If the initial concentration of 9_3.gif is 0.200 M, what are the equilibrium concentrations of 9_4.gif and 9_5.gif?

Answers

Answer:

[tex][N_2]_{eq}=[H_2]_{eq}=0.09899M[/tex]

[tex][NO]_{eq}=0.00202M[/tex]

Explanation:

Hello,

In this case, for the given chemical reaction:

[tex]2NO\rightleftharpoons N_2+O_2[/tex]

We know the equilibrium constant and equilibrium expression:

[tex]Kc=2.4x10^3=\frac{[N_2][O_2]}{[NO]^2}[/tex]

That in terms of the reaction extent [tex]x[/tex] (ICE procedure) we can write:

[tex]2.4x10^3=\frac{x*x}{(0.2M-2*x)^2}[/tex]

In such a way, solving for [tex]x[/tex] by using a quadratic equation or solver, we obtain:

[tex]x_1=0.09899M\\x_2=0.1010M[/tex]

Clearly the solution is 0.09899M since the other value will result in a negative equilibrium concentration of NO. In such a way, the equilibrium concentrations of all the species are:

[tex][N_2]_{eq}=[H_2]_{eq}=x=0.09899M[/tex]

[tex][NO]_{eq}=0.2M-2*0.09899M=0.00202M[/tex]

Regards.

Compound A is an alkene that was treated with ozone to yield only (CH3CH2CH2)2C=O. Draw the major product that is expected when compound A is treated with a peroxy acid (RCO3H) followed by aqueous acid (H3O+).

Answers

Answer:

2,2,3,3-tetrapropyloxirane

Explanation:

In this case, we have to know first the alkene that will react with the peroxyacid. So:

What do we know about the unknown alkene?

We know the product of the ozonolysis reaction (see figure 1). This reaction is an oxidative rupture reaction. Therefore, the double bond will be broken and we have to replace the carbons on each side of the double bond by oxygens. If [tex](CH_3CH_2CH_2)_2C=O[/tex] is the only product we will have a symmetric molecule in this case 4,5-dipropyloct-4-ene.

What is the product with the peroxyacid?

This compound in the presence of alkenes will produce peroxides. Therefore we have to put a peroxide group in the carbons where the double bond was placed. So, we will have as product 2,2,3,3-tetrapropyloxirane. (see figure 2)

Fireworks are chemical reactions that release energy. Which of these phenomena are caused by chemical reactions that release energy? If you’re not sure, make a guess.

Answers

Answer:

All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. Endothermic reactions absorb energy, and exothermic reactions release energy. The law of conservation of energy states that matter cannot be created or destroyed.

2.Which of the alcohols listed below would you expect to react most rapidly with PBr3?A)CH3CH2CH2CH2CH2CH2OHB)(CH3CH2)2CH(OH)CH2CH3C)(CH3CH2)2CHOHCH3D)(CH3CH2)3COHE)(CH3CH2)2C(CH3)OH

Answers

Answer:

A) CH3CH2CH2CH2CH2CH2OH

Explanation:

For this question, we have the following answer options:

A) CH3CH2CH2CH2CH2CH2OH

B) (CH3CH2)2CH(OH)CH2CH3

C) (CH3CH2)2CHOHCH3

D) (CH3CH2)3COH

E) (CH3CH2)2C(CH3)OH

We have to remember the reaction mechanism of the substitution reaction with [tex]PBr_3[/tex]. The idea is to generate a better leaving group in order to add a "Br" atom.

The [tex]PBr_3[/tex] attacks the "OH" generation new a bond to P (O-P bonds are very strong), due to this new bond we will have a better leaving group that can remove the oxygen an allow the attack of the Br atom to generating a new C-Br bond. This is made by an Sn2 reaction. Therefore we will have a faster reaction with primary substrates. In this case, the only primary substrate is molecule A. So, "CH3CH2CH2CH2CH2CH2OH" will react faster.

See figure 1

I hope it helps!


How has the work of chemists affected the environment over the years?

Answers

Answer:

Chemistry is one of the causes for global warming, and in some cases it can even cause certain illnesses.

Answer:

Chemists have both hurt the environment and helped the environment by their actions.

Explanation:

<3

13. Arrange each group of units from smallest to
largest
a)km, mm, cm, m
b) mg, kg, g
C) L, mL
d) s, ms, min, h

Answers

Answer:

A. mm,cm,m,Km

B. mg, g, Kg

C. mL,L

D. ms, s, min, h

Explanation:

What is the edge length of a face-centered cubic unit cell that is made of of atoms, each with a radius of 154 pm

Answers

Answer:

The edge length of a face-centered cubic unit cell is 435.6 pm.

Explanation:

In a face-centered cubic unit cell, each of the eight corners is occupied by one atom and each of the six faces is occupied by a single atom.

Hence, the number of atoms in an FCC unit cell is:

[tex] 8*\frac{1}{8} + 6*\frac{1}{2} = 4 atoms [/tex]

In a face-centered cubic unit cell, to find the edge length we need to use Pythagorean Theorem:

[tex] a^{2} + a^{2} = (4R)^{2} [/tex]     (1)

Where:

a: is the edge length

R: is the radius of each atom = 154 pm      

By solving equation (1) for "a" we have:

[tex] a = 2R\sqrt{2} = 2*154 pm*\sqrt{2} = 435.6 pm [/tex]    

Therefore, the edge length of a face-centered cubic unit cell is 435.6 pm.   

I hope it helps you!

A student is using a coffee-cup calorimeter to determine the enthalpy change of the endothermic reaction of two aqueous solutions. After both solutions are added to the cup, the student neglects to put the lid on the cup. This would cause the magnitude of the calculated ΔH° value to be: the answer is: too small, since the solution will absorb heat from the room. But why? Wouldn't depend on if the reaction releases or absorbs heat. Wouldn't it be too large because heat escapes the cup? I'm so confused

Answers

Answer:

Explanation:

In all calorimetric experiment , the calorimeter must be isolated from the surrounding . Otherwise the heat change in the experiment can not be determined with precision .

The reaction is endothermic . Hence, there is lowering of temperature due to absorption of heat in the reaction equal to ΔH°. The value of ΔH° can be calculated by measuring fall in the temperature of the content . The fall in the temperature will be less when heat is allowed to come from the surrounding . Less fall of temperature will result in less ΔH° to be calculated .

Hence in the given experiment , if the student neglects to put lid on the cup , the experiment will give less value of ΔH°.

Draw a picture of what you imagine solid sodium chloride looks like at the atomic level. (Do NOT draw Lewis structures.) Make sure to include a key. Then describe what you've drawn and any assumptions you are making.

Answers

Answer:

Kindly check the explanation section.

Explanation:

PS: kindly check the attachment below for the required diagram that is the diagram showing solid sodium chloride looks like at the atomic level.

The chemical compound known as sodium chloride, NaCl has Molar mass: 58.44 g/mol, Melting point: 801 °C and

Boiling point: 1,465 °C. The structure of the solid sodium chloride is FACE CENTRED CUBIC STRUCTURE. Also, solid sodium chloride has a coordination number of 6: 6.

In the diagram below, the positive sign shows the sodium ion while the thick full stop sign represent the chlorine ion.

The NaCl has been the ionic structure with an equal number of sodium and chlorine ions bonded.

In the structure, there has been each Na ion bonded with the Cl ions. There has been the transfer of electrons between the structure in order to attain a stable configuration.

The expected structure of the NaCl would be the image attached below.

The image has been the cubic structure of NaCl. With the presence of Na ions at the vertex of the structure, there has been the presence of the Cl ion with every Na ion for the electron transfer.

For more information about the structure of NaCl, refer to the link:

https://brainly.com/question/2729718

g . Calculate the molar concentration for each of the following solutions. (a) 1.50 g NaCl in 100.0 mL of solution (b) 1.50 g K2Cr2O7 in 100.0 mL of solution (c) 5.55 g CaCl2 in 125 mL of solution (d) 5.55 g Na2SO4 in 125 mL of solution

Answers

Answer:

(a) [tex]M=0.257M[/tex]

(b) [tex]M=0.0510M[/tex]

(c) [tex]M =0.500M[/tex]

(d) [tex]M= 0.391M[/tex]

Explanation:

Hello,

In this case, since the molarity or molar concentration of a solution is computed by dividing the moles of solute by the volume of solution in liters, we proceed as follows:

(a) The molar mass of sodium chloride is 58.45 g/mol and the volume in liters is 0.100 L, therefore, the molarity is:

[tex]M=\frac{1.50gNaCl}{0.100L} *\frac{1molNaCl}{58.45gNaCl} =0.257M[/tex]

(b) The molar of potassium dichromate is 294.2 g/mol and the volume in liters is 0.100 L, therefore, the molarity is:

[tex]M=\frac{1.50gK_2Cr_2O_7}{0.100L} *\frac{1molK_2Cr_2O_7}{294.2gK_2Cr_2O_7} =0.0510M[/tex]

(c) The molar of calcium chloride is 111 g/mol and the volume in liters is 0.125 L, therefore, the molarity is:

[tex]M=\frac{5.55gCaCl_2}{0.100L} *\frac{1molCaCl_2}{111gCaCl_2} =0.500M[/tex]

(d) The molar of sodium sulfate is 142 g/mol and the volume in liters is 0.125 L, therefore, the molarity is:

[tex]M=\frac{5.55gNa_2SO_4}{0.100L} *\frac{1molNa_2SO_4}{142gNa_2SO_4} = 0.391M[/tex]

Best regards.

what is the oxidation state of the oxygen atoms in co2,h2o and o2 and what does this information tell you about photosynthesis and respiration

Answers

Answer:

-2, -2 and 0.

- Respiration is a process in which energy is produced and photosynthesis is a process in which energy is used.

Explanation:

Hello,

In this case, oxygen is a substance that is used for animals and us to acquire the energy necessary for several functions by the cellular respiration (we also need glucose), besides, it is a product of the photosynthesis carried out by vegetable cells (plants). Moreover, carbon dioxide and water are used by the plants to produce oxygen we need as well as glucose via the aforementioned photosynthesis, thus, both chemical reactions are shown below:

[tex]C_6H_{12}O_6+6O_2\rightarrow 6CO_2+6H_2O\ \ \ respiration\\\\6CO_2+6H_2O\rightarrow C_6H_{12}O_6+6O_2\ \ \ photosynthesis[/tex]

In such a way, since the oxygen in carbon dioxide and water has an oxidation state of -2 (reduced form) we can say that the respiration is a process in which energy is produced and since the oxygen yielded during the photosynthesis has an oxydation state of 0, we can say that photosynthesis is a process in which energy is used.

Best regards.

105/22 • (1.251 - 0.620)=

Answers

Answer:

105/22*(1.251-0.620)

105/22*0.631

4.772*0.631

3.011132

Hope it helps

Answer:

3.0

Explanation:

First, complete the operations inside the parenthesis according to the normal rules for significant figures. Because there are subsequent calculations, keep at least one extra significant figure when possible: (4.7727) × (0.631).

The final product will be rounded to two significant figures because it can’t be more precise than the least precise number in the problem, 22. The final product is 3.0.

A piece of plastic sinks in oil but floats in water. Place these three substances in order from lowest density to greatest density.

Answers

Answer:

[tex]\rho _{oil}<\rho _{plastic}<\rho _{water}[/tex]

Explanation:

Hello,

In this case, since water and oil are immiscible due to the oil's nonpolarity and water's polarity, when mixed, the oil remains on the water since it is less dense than water. In such a way, for a plastic sunk in the oil and floating on the water (in middle of them) we can conclude that the plastic have a mid density, therefore, the required organization is:

[tex]\rho _{oil}<\rho _{plastic}<\rho _{water}[/tex]

Best regards.

What is the mass number of an element

Answers

Answer:

A (Atomic mass number or Nucleon number)

Explanation:

The mass number is the total number of protons and nucleons in an atomic nucleus.

Hope this helps.

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In the reaction 2 AgI + HgI 2 → Ag 2HgI 4, 2.00 g of AgI and 3.50 g of HgI 2 were used. What is the limiting reactant?

Answers

Answer:

AgI I the limiting reactant.

Explanation:

The balanced equation for the reaction is given below:

2AgI + HgI2 → Ag2HgI4

Next, we shall determine masses AgI and HgI2 that reacted from the balanced equation.

This is illustrated below:

Molar mass of Agl = 108 + 127 = 235 g/mol

Mass of AgI from the balanced equation = 2 x 235 = 470 g

Molar mass of HgI2 = 201 + (2x127) = 455 g/mol

Mass of HgI2 from the balanced equation = 1 x 455 = 455 g

From the balanced equation above,

470 g of AgI reacted with 455 g of HgI2.

Finally, we shall determine the limiting reactant as follow:

From the balanced equation above,

470 g of AgI reacted with 455 g of HgI2.

Therefore, 2 g of AgI will react with

= (2 x 455)/470 = 1.94 g of HgI2.

From the calculations made above, we can see that only 1.94 g out of 3.50 g of HgI2 given is needed to react completely with 2 g of AgI.

Therefore, AgI I the limiting reactant.

The argon atoms are excited into an excited state before emitting the 488.0 nm laser. It is known that the energy of the first ionization energy of argon is 1520 kJ mol-1. What is the energy level of the excited state (in unit eV) lies below the vacuum energy level (0 eV)

Answers

Answer:

Explanation:

Given that:

The argon atoms are excited into an excited state before emitting the 488.0 nm laser.

the energy of the first ionization energy of argon is 1520 kJ mol-1.

SInce 1 eV = 96.49 kJ/mol

Therefore, the energy of the first ionization energy of argon in eV is = ( 1520/ 96.49) eV

=  15.75 eV

To find where  the energy level of the excited state lies below the vacuum energy level, let's first determine, the energy liberated by using planck expression.

[tex]E = \dfrac{hc}{\lambda}[/tex]

[tex]E = \dfrac{6.6 \times 10^{-34} \times 3 \times 10^8}{488 \times 10^{-9}}[/tex]

[tex]E = \dfrac{1.98 \times 10^{-25}}{488 \times 10^{-9}}[/tex]

[tex]E = \dfrac{1.98 \times 10^{-25}}{488 \times 10^{-9}}[/tex]

[tex]E =4.057 \times 10^{-19} \ J[/tex]

Converting Joules (J) to eV ; we get,

[tex]E =\dfrac{4.057 \times 10^{-19}}{1.6 \times 10^{-19}}[/tex]

E = 2.53 eV

The energy levels of the first exited state = -13.223 eV

Calculate the entropy change in the surroundings associated with this reaction occurring at 25∘C. Express the entropy change to three significant figures and include the appropriate units.

Answers

Answer:

That means that if you are calculating entropy change, you must multiply the enthalpy change value by 1000. So if, say, you have an enthalpy change of -92.2 kJ mol-1, the value you must put into the equation is -92200 J mol-1

The entropy change in the surroundings associated with this reaction occurring at 25 degree C is calculated as ΔS = -ΔH/T J/K.

What is entropy?

Entropy is a quantity which gives idea about the randomness or arrangement of atoms or molecules present in any sample.

Entropy change will be calculated as:
ΔS = -ΔH/T, where

ΔH = chnage in enthalpy (J/mole)

T = temperature (K)

So to calculate the entropy change first we have to know about the value of enthalpy in joules and then divide it by the temperature.

Hence the unit of entropy is joule per kelvin.

To know more about entropy, visit the below link:
https://brainly.com/question/6364271

A solution containing a unknown ionic compound, vigorously bubbles when hydrochloric acid (HCl) is added to the solution. This might indicate that the solution contains which anion?

Answers

Answer:

CO3^2-

Explanation:

In qualitative analysis, we try to use chemical reactions to determine the composition of an unknown substance. The addition of certain reagents to the unknown solution gives certain results that show the presence or absence of certain species from the unknown sample.

When dilute HCl is added to an unknown sample and effervescence is observed, then the unknown sample must contain CO3^2- or HCO3^-. The presence of these species is confirmed if the gas evolved is passed through limewater and the gas turns limewater milky.

4. A 0.100 M solution of NaOH is used to titrate an HCl solution of unknown concentration. To neutralize the solution, an average volume of
the titrant was 38.2 mL. The starting volume of the HCI solution was 20 ml. What's the concentration of the HCI?
O A.0.284 M
B. 3.34 M
C. 0.191 M
D. 0.788 M​

Answers

Answer:

C. 0.191 M

Explanation:

Our goal for this question, is to calculate the concentration of the HCl solution. For this, in the experiment, a solution of NaOH was used to find the moles of HCl. Therefore, our first step is to know the reaction between HCl and NaOH:

[tex]HCl~+~NaOH~->~NaCl~+~H_2O[/tex]

The "titrant" in this case is the NaOH solution. If we know the concentration of NaOH (0.100M) and the volume of NaOH (38.2 mL=0.0382 L), we can calculate the moles using the molarity equation:

[tex]M=\frac{mol}{L}[/tex]

[tex]0.100~M=\frac{mol}{0.0382~L}[/tex]

[tex]mol=0.100~M*0.0382~L=0.0382~mol~of~NaOH[/tex]

Now, in the reaction, we have a 1:1 molar ratio between HCl and NaOH (1 mol of HCl is consumed for each mole of NaOH added). Therefore we will have the same amount of moles of HCl in the solution:

[tex]0.0382~mol~of~NaOH\frac{1~mol~HCl}{1~mol~NaOH}=0.0382~mol~HCl[/tex]

If we want to calculate the molarity of the HCl solution we have to divide by the litters of HCl used in the experiment (20 mL= 0.02 L):

[tex]\frac{0.0382~mol~HCl}{0.02~L}~=~0.191~M[/tex]

The concentration of the HCl solution is 0.191 M

I hope it helps!

What is the atomic mass for Helium (He)? Question 5 options: 8 2 3 4

Answers

It is 2 because if you have a chart that shown all the elements at the top left corner it would show a number and that is the atomic number
Other Questions
Nine and one-half less than four and one-half times a number is greater than 62.5. Which of the following represents the solution set of this problem?(16, positive infinity)(Negative 16, positive infinity)(Negative infinity, 16)(Negative infinity, Negative 16) Choose the inequality that represents the following graph. . En el tringulo ABC, la medida del ngulo exterior en el vrtice B es el triple de la medida del ngulo C y la mediatriz de BC corta a AC en el punto F. sabiendo que FC=12. Calcular AB. The approach to measuring GDP that adds together compensation to employees, rents, interest income, dividends, undistributed corporate profits, proprietors' income, indirect business taxes, the consumption of fixed capital, and net foreign factor income earned in the United States is the: Yo help me real quick? Based on the essays central ideas, what is Emerson trying to convince the reader to think or do? According to the FTC's historical guidelines for mergers, would the FTC approve a merger between two firms that would result in an HHI of 1,025 after the merger?A: Maybe. The FTC would scrutinize the merger and make a case-by-case decision.B: Yes, the FTC would ignore the merger and allow it to go through.C: No, the FTC would probably challenge the merger.2. Instead of defining a market and counting up total sales, what are antitrust regulators looking at today when determining whether to allow a merger or not?A: HHIB: industry competitionC: four-firm concentration ratioD: innovation3. Price cap regulations are a market regulatory device governments utilize, where the top price a firm can charge is locked in for a defined period of time. All of the following statements are true, except:_________.A: The government sets a price by looking at the firm's average costs and then adding a normal rate of profit.B: The firm can make high profits by producing a higher quantity than expected.C: The firm can make high profits by producing at lower costs.D: The government sets a price level for a few years. Which of the following details from the story best helps the reader imagine the setting of the competition? A. There were many different types of dogs, but none like Sporty. B. The owners had to stand behind a yellow line that had been spray-painted across a 40 foot by 80 foot grassy field. C. Sporty sprinted, launched himself into the air, did a forward somersault, and caught the Frisbee before landing on all fours. D. The rival, a sleek Boxer named Raj, effortlessly bounded and gracefully plucked the Frisbee from the sky. Winnwbagel corp. currently sells 25,200 motor homes per year at 37,800 each, and 10,080 luxury motor coaches per year at $71,400 each. The company wants to introduce a new portable camper to fill out its product line., it hopes to sell 15,960 of these campers per year at $10,080 each. An independent consultant has determined that if the company introduces the new campers, it should boost the sales of its existing motor homes by 3,780 units per year, and reduce the sales of its motor coaches by 756 units per year. What is the amount to use as the annual sales figure when evaluating this project? a. $237,293,280.b. $262,271,520. c. $357,739,200.d. $95739200.e. $160,876,800.f. $249,782,400. Given v(x) = g(x) (3/2*x^4 + 4x 1), find v'(2). On January 1, a company issued 5%, 15-year bonds with a face amount of $80 million for $59,249,660 to yield 8%. Interest is paid semiannually. What was the interest expense at the effective interest rate on the December 31 annual income statement White light containing wavelengths from 410 nm to 750 nm falls on a grating with 7800 slits/cm. Part APart complete How wide is the first-order spectrum on a screen 3.20 m away Please help...25 points In a proceeds transaction: I. a customer directs that a position be sold; and the funds generated from the sale be used to buy another position II. a customer sells short securities "against the box" III. 2 separate mark-ups or commissions are charged IV. a combined mark-up or commission is charged (05.01) A window is 4 feet and 8 feet tall. A manufacturer wants to use a scale factor of 1.5 to enlarged a window. What will the area of the wind will be after it is enlarged? Braxton's Cleaning Company stock is selling for $33.25 per share based on a required return of 11.7 percent. What is the the next annual dividend if the growth rate in dividends is expected to be 4.5 percent indefinitely? Portage Bay Enterprises has $1 million in excess cash, no debt, and is expected to have free cash flow of $11 million next year. Its FCF is then expected to grow at a rate of 5% per year forever. If Portage Bay's equity cost of capital is 10% and it has 4 million shares outstanding, what should be the price of Portage Bay stock? Evaluate the statement: "If there are sacrifices to be made for human progress, is it not essential to hold to the principle that those to be sacrificed must make the decision themselves?" A standardized exam's scores are normally distributed. In a recent year, the mean test score was and the standard deviation was . The test scores of four students selected at random are , , , and . Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for is nothing. (Round to two decimal places as needed.) The z-score for is nothing. (Round to two decimal places as needed.) The z-score for is nothing. (Round to two decimal places as needed.) The z-score for is nothing. (Round to two decimal places as needed.) Which values, if any, are unusual? Select the correct choice below and, if necessary, fill in the answer box within your choice. A. The unusual value(s) is/are nothing. (Use a comma to separate answers as needed.) B. None of the values are unusual. A news article estimated that only 5% of those age 65 and older who prefer to watch the news, rather than to read or listen, watch the news online. This estimate was based on a survey of a large sample of adult Americans. Consider the population consisting of all adult Americans age 65 and older who prefer to watch the news, and suppose that for this population the actual proportion who prefer to watch online is 0.05. A random sample of n = 100 people will be selected from this population and p, the proportion of people who prefer to watch online, will be calculated. (a) What are the mean and standard deviation of the sampling distribution of p? (Round your standard deviation to four decimal places.(b) Is the sampling distribution of p approximately normal for random samples of size n 100? Explain. i. The sampling distribution of p is approximately normal because np is less than 10. ii. The sampling distribution of p is approximately normal because np is at least 10. iii. The sampling distribution of p is not approximately normal because np is less than 10 iv. The sampling distribution of p is not approximately normal because np is at least 10 v. The sampling distribution of p is not approximately normal because n(1 - p) is less than 10. (c) Suppose that the sample size is n = 400 rather than n = 100, what are the values for the mean and standard deviation when n=400? Does the change in sample size affect the mean and standard deviation of the sampling distribution of p? If not, explain why not. i. When the sample size increases, the mean increases. ii. When the sample size increases, the mean decreases. iii. When the sample size increases, the mean stays the same. iv. The sampling distribution is always centered at the population mean, regardless of sample size. v. When the sample size increases, the standard deviation increases. vi. When the sample size increases, the standard deviation decreases.