If the mole fraction of Na2S in an aqueous solution is 0.125,
what is the weight/weight %
(percent by mass) of Na2S?

Answer:

c

Explanation:

Answer:

[tex]\frac{40}{18}Ar => \frac{40}{17}Cl + \frac{0}{1}e\\[/tex]

Explanation:

The process of positron emission is better understood by the following reaction:

Positron emission may be defined as a subordinate type of radioactive decay called which is effectively known as beta decay. Due to this emission, a proton that is present inside a radionuclide nucleus significantly transformed into a neutron while liberating a positron and an electron neutrino.

According to the context of this question, Argon-40 undergoes the process of beta decay. Through which X element is formed which is known as chlorine. The atomic number (Z) of chlorine is 17, while the atomic mass (A) is 40 which is as identical to argon.

Therefore, the appropriate values for A and Z and the chemical symbol for X are 40 and 17 respectively.

To learn more about Positron emission, refer to the link:

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Answer:

A. The Swallowing reflex

Explanation:

Dysphagia Is a a condition that makes swallowing difficult.

Answer:

There are several roles of HCl in the digestive system. Some of them are as follows:

Answer:

The hardness is more than 2.5. Hope this helps.

Answer:

The hardness is more than 2.5.

Explanation:

Answer:

The importance of learning is that it helps the individual to acquire the necessary skills through learning and knowledge so that he can achieve his set goals. An important fact about learning is that it is a means to improve knowledge and gain skills that will help in reaching specific goals

Explanation:

The importance of learning is that it helps the individual to acquire the necessary skills through learning and knowledge so that he can achieve his set goals. An important fact about learning is that it is a means to improve knowledge and gain skills that will help in reaching specific goals

Answer:

[tex]\Delta V = 234.736\,mL[/tex]

Explanation:

The quantity of moles of ethanol in the solution is:

[tex]n_{C_{2}H_{5}OH} = \left(\frac{597\,mL}{1000\,mL} \right)\cdot \left(8.35\,\frac{mol}{L} \right)[/tex]

[tex]n_{C_{2}H_{5}OH} = 4.985\,mol[/tex]

The mass and volume of ethanol in the solution are, respectively:

[tex]m_{C_{2}H_{5}OH} = (4.985\,mol)\cdot \left(46.07\,\frac{g}{mol} \right)[/tex]

[tex]m_{C_{2}H_{5}OH} = 229.658\,g[/tex]

[tex]V_{C_{2}H_{5}OH} = \frac{229.658\,g}{0.7893\,\frac{g}{mL} }[/tex]

[tex]V_{C_{2}H_{5}OH} = 290.964\,mL[/tex]

The difference between the total volume of water and ethanol mixed to prepare the solution and the actual volume of solution is:

[tex]\Delta V = (525\,mL+597\,mL) - (597\,mL + 290.964\,mL)[/tex]

[tex]\Delta V = 234.736\,mL[/tex]

The difference in volume between the total volume of water and ethanol is ΔV =234.736 mL.

The quantity of moles of ethanol in the solution is:

[tex]nC_2H_5OH=\frac{597mL}{1000mL} *8.35mol/L\\\\nC_2H_5OH=4.985 moles[/tex]

The mass and volume of ethanol in the solution are, respectively:

[tex]mC_2H_5OH=4.985moles*46.07g/mol\\\\mC_2H_5OH=229.685g[/tex]

[tex]VC_2H_5OH=\frac{229.685g}{0.7893g/mL} \\\\VC_2H_5OH=290.964mL[/tex]

The difference between the total volume of water and ethanol mixed to prepare the solution and the actual volume of solution is:

ΔV= (525mL+597mL)- (597mL + 290.964 mL)

ΔV= 234.736mL

Find more information about Moles here:

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Answer:

[tex]m_{PbI_2}=18.2gPbI_2[/tex]

Explanation:

Hello,

In this case, we write the reaction again:

[tex]Pb(NO_3)_2(aq) + 2 KI(aq)\rightarrow PbI_2(s) + 2 KNO_3(aq)[/tex]

In such a way, the first thing we do is to compute the reacting moles of lead (II) nitrate and potassium iodide, by using the concentration, volumes, densities and molar masses, 331.2 g/mol and 166.0 g/mol respectively:

[tex]n_{Pb(NO_3)_2}=\frac{0.14gPb(NO_3)_2}{1g\ sln}*\frac{1molPb(NO_3)_2}{331.2gPb(NO_3)_2} *\frac{1.134g\ sln}{1mL\ sln} *96.7mL\ sln\\\\n_{Pb(NO_3)_2}=0.04635molPb(NO_3)_2\\\\n_{KI}=\frac{0.12gKI}{1g\ sln}*\frac{1molKI}{166.0gKI} *\frac{1.093g\ sln}{1mL\ sln} *99.8mL\ sln\\\\n_{KI}=0.07885molKI[/tex]

Next, as lead (II) nitrate and potassium iodide are in a 1:2 molar ratio, 0.04635 mol of lead (II) nitrate will completely react with the following moles of potassium nitrate:

[tex]0.04635molPb(NO_3)_2*\frac{2molKI}{1molPb(NO_3)_2} =0.0927molKI[/tex]

But we only have 0.07885 moles, for that reason KI is the limiting reactant, so we compute the yielded grams of lead (II) iodide, whose molar mass is 461.01 g/mol, by using their 2:1 molar ratio:

[tex]m_{PbI_2}=0.07885molKI*\frac{1molPbI_2}{2molKI} *\frac{461.01gPbI_2}{1molPbI_2} \\\\m_{PbI_2}=18.2gPbI_2[/tex]

Best regards.

Answer:

Mass PbI2 = 18.19 grams

Explanation:

Step 1: Data given

Volume solution = 99.8 mL = 0.0998 L

mass % KI = 12.0 %

Density = 1.093 g/mL

Volume of the other solution = 96.7 mL = 0.967 L

mass % of Pb(NO3)2 = 14.0 %

Density = 1.134 g/mL

Step 2: The balanced equation

Pb(NO3)2(aq) + 2 KI(aq) ⇆ PbI2(s) + 2 KNO3(aq)

Step 3: Calculate mass

Mass = density * volume

Mass KI solution = 1.093 g/mL * 99.8 mL

Mass KI solution = 109.08 grams

Mass KI solution = 109.08 grams *0.12 = 13.09 grams

Mass of Pb(NO3)2 solution = 1.134 g/mL * 96.7 mL

Mass of Pb(NO3)2 solution = 109.66 grams

Mass of Pb(NO3)2 solution = 109.66 grams * 0.14 = 15.35 grams

Step 4: Calculate moles

Moles = mass / molar mass

Moles KI = 13.09 grams / 166.0 g/mol

Moles KI = 0.0789 moles

Moles Pb(NO3)2 = 15.35 grams / 331.2 g/mol

Moles Pb(NO3)2 = 0.0463 moles

Step 5: Calculate the limiting reactant

For 1 mol Pb(NO3)2 we need 2 moles KI to produce 1 mol PbI2 and 2 moles KNO3

Ki is the limiting reactant. It will completely be consumed ( 0.0789 moles). Pb(NO3)2 is in excess. There will react 0.0789/2 = 0.03945 moles. There will remain 0.0463 - 0.03945 = 0.00685 moles

Step 6: Calculate moles PbI2

For 1 mol Pb(NO3)2 we need 2 moles KI to produce 1 mol PbI2 and 2 moles KNO3

For 0.0789 moles KI we'll have 0.0789/2 = 0.03945 moles PbI2

Step 7: Calculate mass of PbI2

Mass PbI2 = moles PbI2 * molar mass PbI2

Mass PbI2 = 0.03945 moles * 461.01 g/mol

Mass PbI2 = 18.19 grams

Answer:

C) Integumentary, nervous, muscular

Explanation:

When a human body touches a hot stove , our sense organ which is integumen first of all receives the impulse of heat . The impulse is transformed into electrical signal which is transmitted to brain which is a part of nervous system . Then brain processes it and command signal is sent to muscle of hand to move it away from that place . Hence the order is

Integumentary, nervous, muscular .

Answer:

The second one

Explanation:

Because not only did I take a castle learning in this today but c2h4 has 6 covalent bonds

There are several types of molecules that have multiple bond. A molecule of which compound has a multiple covalent bond is C2H4.

Covalent bonding is the sharing of one or more electron pairs. In many covalent bonding situations,

Multiple chemical bonds exist when there is more than one electron pair that is being shared.

A nitrogen atom often fill its octet by sharing three electrons with another nitrogen atom thereby creating three covalent bonds.

Multiple bonds are commonly found in organic compound and they have carbon molecules.

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Answer:

A chemical reaction is a process in which one or more substances, also called reactants, are converted to one or more different substances, known as products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.

Explanation:

Hopefully this is what you needed

Answer:

D) SrCO3(s) + 2 HNO2(aq) → Sr(NO2)2 + H2O + CO2(g)

Explanation:

When an acid react with carbonate, it produces nitrate, carbon-dioxide gas and water molecule. When nitrous acid react with Strontium carbonate, three products are formed i. e. Strontium nitrate, carbon-dioxide gas and water. In the reaction, both nitrous acid and Strontium carbonate exchange their partners with each other and forming a different products.

Answer:

Option E is correct.

The net ionic equation is given as

SrCO₃(s) + 2H⁺ → Sr²⁺ + H₂O + CO₂(g)

Explanation:

When acids react with carbonate compounds, it leads to the liberation of CO₂, hence, when an aqueous solution of HNO₂ is poured onto a solid pile of SrCO₃, the balanced overall equation is given as

SrCO₃(s) + 2HNO₂(aq) → Sr(NO₂)₂ + H₂O + CO₂(g)

But for the net ionic reaction, it is obtained by eliminating ions that occur on both sides of the overall reaction. Note that ions exist onlubone the aqueous compounds.

Hence, the two aqueous compounds that exist in the balanced overall equation are

2HNO₂(aq) on the left hand side and Sr(NO₂)₂ on the right hand side

In their ionic form, 2HNO₂ ⇌ 2H⁺ + 2NO₂⁻

And Sr(NO₂)₂ ⇌ Sr²⁺ + 2NO₂⁻

And it is evident that the ion that occurs on both sides and needs to be deleted is NO₂⁻,

Hence, the net ionic equation is

SrCO₃(s) + 2H⁺ → Sr²⁺ + H₂O + CO₂(g)

Hope this Helps!!!

Answer:

Substance c in J/gm K

Copper               0.386

Aluminum      0.900

Lead              0.128

Iron                     0.450

Explanation:

Answer:

the European countries grew together.

Explanation:

Europe saw human inflows from east and southeast.

the Roman Empire came to dominate the entire Mediterranean basin.

European politics from 1947 to 1989 made the European countries grew together.

Answer:

I believe it is C.Shelter.

Answer:

C

Explanation:

The butterflies use the trees for shelter, because the trees protect them from the weather and the cold air.

Answer:

120.4 gradius Celcius

Explanation:

Please see the step-by-step solution in the picture attached below.

Hope this answer can help you. Have a nice day!

Answer:

.01

Explanation:

H30+=10^-pH

- Hope that helps! Please let me know if you need further explanation.

Answer: I believe it's convection

Good luck and I hope this helps!!

Answer: Convection

Explanation: Edge

After the body is cleaned, the body is weighed and measured before being placed on the autopsy table for reexamination. The autopsy table is typically a slanted, aluminum table with raised edges that has several faucets and drains used to wash away collecting blood during the internal investigation.

Answer:

A table used to scientifically determine the cause of death of a human or animal

Explanation:

Answer:

K^+ and NO3^-

Explanation:

In a balanced ionic equation, we usually see the species that react to yield the main product in the reaction.

Consider the reaction;

Pb(NO3)2(aq) +2 KI(aq) -------> PbI2(s) + 2KNO3(aq)

The main product in this reaction is PbI2. Hence the balanced ionic equation is;

Pb^2+(aq) + 2I^-(aq) ------> PbI2(s)

Notice that K^+ and NO3^- did not participate in this reaction. All ions that are part of the molecular equation but do not participate in the ionic reaction equation are called spectator ions. Hence K^+ and NO3^- are spectator ions in this reaction as can be seen clearly above.

Answer:

Heat energy = 8669.32J

Explanation:

Mass = 122g

Change in temperature ∇T = 17°C

Specific heat capacity (c) = 4.18J/g°C

Heat energy (Q) = ?

Heat energy (Q) = mc∇T

Q = heat energy

M = mass of the substance

C = specific heat capacity of the substance

∇T = change in temperature of the substance

Q = mc∇T

Q = 122 × 4.18 × 17

Q = 8669.32J

The heat energy required to raise 122g of water by 17°C is 8669.32J

Answer:

[tex]Q=8669.3J=8.67kJ[/tex]

Explanation:

Hello,

In this case, we can compute the absorbed heat of water needed to raise its temperature by 17 °C by using the following formula:

[tex]Q=mCp\Delta T[/tex]

In this case, the mass is 122 g, the specific heat 4.18 J/(g°C) and the temperature change 17 °C, hence the heat turns out:

[tex]Q=122g*4.18\frac{J}{g\°C}*17\°C\\ \\Q=8669.3J=8.67kJ[/tex]

Best regards.

Answer:

Ionic bonds

Explanation:

It rymes.  haha i dont even know how to spell it! ;)

Answer:

Option C

Explanation:

A double displacement reaction is the one in which two chemical compounds having a cation and anion in each exchange their positive and negative ions thereby forming new compounds or products.

Here,

The first compound [tex]PbCl_2[/tex] has a positive ion [tex]Pb[/tex] and negative ion [tex]Cl^-[/tex]

Like wise the second compound [tex]Ag(NO_3)[/tex] has a positive ion [tex]Ag[/tex] and negative ion [tex]NO_3[/tex]

The new compounds will be formed when cation of one compound attaches with the anion of other compound. Hence the new compounds are

[tex]Pb(NO_3)_2[/tex]

[tex]AgCl[/tex]

This is example of double displacement reaction.

Option C is correct

Answer:The answer to this question comes from experiments done by the scientist Robert Boyle in an effort to improve air pumps. In the 1600's, Boyle measured the volumes of gases at different pressures. Boyle found that when the pressure of gas at a constant temperature is increased, the volume of the gas decreases. when the pressure of gas is decreased, the volume increases. this relationship between pressure and volume is called Boyle's law.

Explanation: So, at constant temperature, the answer to your answer is: the volume decreases in the same ratio as the ratio of pressure increases.

BUT, in general, there is not a single answer to your question. It depend by the context.

For example, if you put the gas in a rigid steel tank (volume is constant), you can heat the gas, so provoking a pressure increase. But you won't get any change in volume.

Or, if you heat the gas in a partially elastic vessel (as a tire or a soccer ball) you will get both an increase of volume AND an increase of pressure.

FINALLY if you inflate a bubblegum ball, the volume will be increased without any change in pressure and temperature, because you have increased the NUMBER of molecules in the balloon.

There are many other ways to change volume and pressure of a gas that are different from the Boyle experiment.

Answer:

the claim is that when people avoid storms they hide in any secret place in there house

Explanation:

when people do that they don't even have to worry about a single thing that will happen to them

Answer:

The variables in Gay-Lussac's law are the initial temperature (T1), the initial pressure (P1), the final temperature (T2) and the final pressure (P2)....

Explanation:

Answer:

.176 M

Explanation:

set the number of moles of the base equal to the number of moles of acid.

(1.008 mol/L)(26.23 x 10^-3 L)=(150.2x10^-3 L)(x)

x = .176030892 mol/L