pls I need help with these ques. help plsssssssssssssss

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

hEy!!!

Chlorine(CL) is the symbol for the entity that has 17 protons,20 neutrons and 18 electrons.

Hope it will be helpful to you...

Answer:chlorine

Explanation:

Answer:

C

Explanation:

The reflection if sunlight on the water makes the water look silver,gray,white

Answer:

Dissociated state is the predominant one

Explanation:

When a molecule with pKa of 4.52 is in an aqueous solution at pH = 4.0, follows the H-H equation, thus:

pH = pKa + log₁₀ [A⁻] / [HA]

Where [A⁻] is the dissociated state and [HA] represents the protonated state

Replacing:

4.0 = 5.2 + log₁₀ [A⁻] / [HA]

-1.2 = log₁₀ [A⁻] / [HA]

0.063 =  [A⁻] / [HA]

[HA]  = 16 [A⁻]

That means you have 16 times more [HA] than [A⁻] and the dissociated state is the predominant one

Answer:

A. The Swallowing reflex

Explanation:

Dysphagia Is a a condition that makes swallowing difficult.

Answer:

[tex]Q=2091J=2.091kJ[/tex]

Explanation:

Hello,

In this case, the formula we use to compute the heat Q by increasing the temperature, in terms of the mass and the heat capacity is:

[tex]Q=mCp(T_2-T_1)[/tex]

Titanium's heat capacity is 0.544284 J/g°C, thus, the for such temperature increase, the heat results positive as shown below:

[tex]Q=22.6g*0.544284\frac{J}{g^oC}*(1590^oC-1420^oC) \\\\Q=2091J=2.091kJ[/tex]

Best regards.

Answer:

See explaination

Explanation:

1. The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors: Wrong

The addition of 3A group elements inreases the conductivity and make them extrinsic semiconductors( p-type)

2. The conductivity of semiconductors can be increased by the doping process.: Correct

3.As the temperature increases, the conductivity of semiconductors decreases.. wrong

As the temperature increases, the conductivity of semiconductors increases.

4. The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors: Correct : They will create n-type semicoductor.

5.Holes are charge carriers in p-type semiconductors: Correct

6. Electrons are charge carriers in n-type semiconductors: Correct

Answer:

Power, P = 300 W

Explanation:

We have,

Force acting on the box to take it is 300 N

It is moved to a distance of 10 m in 10 seconds

It is required to find the power required to move the box. The rate at which work is done is called power required by an object. It can be given by the formula as follows :

[tex]P=\dfrac{W}{t}\\\\P=\dfrac{Fd}{t}\\\\P=\dfrac{300\times 10}{10}\\\\P=300\ W[/tex]

So, the power required is 300 W.

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:

Avagadro's Law- Gives the relationship between volume and amount of gas in moles when pressure and temperature are held constant. If the amount of gas in a container is increased, the volume increases. ... This means more impacts on the walls of the container and an increase in the pressure.

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:

density

Explanation:

Density is an important measurement. It has an unit: g/mL or kg/L, ...

Evaporation, freezing, melting are the processes in which the substances change their states. Other processes are: condensation, sublimation, deposition.

...

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

Answer:

98.3 gradius Celsius

Explanation:

This problem is solved using the Ideal Gas Equation

pV = nRT

...

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

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

Answer:

[tex]M_2=0.51M[/tex]

Explanation:

Hello,

In this case, for this dilution process, we understand that the moles of the solute (potassium nitrate) remain unchanged upon the addition of diluting water. However, the resulting or final volume includes the added water as shown below:

[tex]V_2=300mL+50mL=350mL[/tex]

In such a way, we are able to relate the solution before and after the dilution by:

[tex]V_1M_1=V_2M_2[/tex]

Hence, we solve for the final molarity as:

[tex]M_2=\frac{M_1V_1}{V_2}=\frac{0.6M*300mL}{350mL}[/tex]

Best regards.

[tex]M_2=0.51M[/tex]

Answer:

The first thing you will need to do is find some information about your element. Go to the Periodic Table of Elements and click on your element. If it makes things easier, you can select your element from an alphabetical listing.

Number of Protons = Atomic Number

Number of Electrons = Number of Protons = Atomic Number

Number of Neutrons = Mass Number - Atomic Number

For krypton:

Number of Protons = Atomic Number = 36

Number of Electrons = Number of Protons = Atomic Number = 36

Number of Neutrons = Mass Number - Atomic Number = 84 - 36 = 48

Explanation:

hope this helps, have a good day :-)

Answer:

Endothermic. The energy is flowing into the molecules causing them to break apart and the ice pop change state.

Answer:

Yes, an autumn day isn’t cold enough to keep an ice pop at freezing temperatures.

Answer:

Specific heat capacity of iron (C) = 0.3 J/GK

Explanation:

Given:

Mass of sample (m) = 125 gram

Change in heat (ΔT) = 20°C - 0°C = 20°C

Absorbed energy (ΔE) = 750 J

Find:

Specific heat capacity of iron (C) = ?

Computation:

⇒ Specific heat capacity of iron (C) = ΔE / [mΔT]

⇒ Specific heat capacity of iron (C) = 750 / [125 × 20]

⇒ Specific heat capacity of iron (C) = 750 / [2,500]

⇒ Specific heat capacity of iron (C) = 0.3 J/GK

Answer:

Specific heat capacity of iron (C) [tex]= 0.3[/tex] J/g°C

Explanation:

As we know that

Specific heat capacity of iron (C) [tex]=\frac{\delta E}{ [m* \delta T]}[/tex]

Where [tex]\delta E[/tex] represents the change in the energy

m represents the mass of the sample and

[tex]\delta T[/tex] represents the change in temperature.

Given:

Mass of sample (m) [tex]= 125[/tex] gram

Change in heat ([tex]\delta T[/tex] ) [tex]20 - 0 = 20[/tex]

Absorbed energy ([tex]\delta E[/tex])[tex]= 750[/tex] J

Substituting the given values in above equation, we get -

Specific heat capacity of iron (C)

[tex]= \frac{750}{125*20}[/tex]

Specific heat capacity of iron (C) [tex]= 0.3[/tex] J/g°C

Answer:

.It is easily synthesized from the reaction of propylene with sulfuric acid, followed by hydrolysis. Isopropyl alcohol (2-propanol) is made by indirect hydration of propylene (CH2CHCH3).… In some cases the hydration of propylene is carried out in one step, using water and a catalyst at high pressure.

Hope it'll help!

stay safe:)

Answer:

1.

[tex]A=69.8\frac{bar}{m^6}\\\\ B=0.00302bar*m^6[/tex]

2. [tex]W=-8.2kPa[/tex]

Explanation:

Hello,

1. In this case, for the given p-V equation, one could use the two states to form a 2x2 linear system of equations in terms of A and B:

[tex]\left \{ {{0.1^2A+0.1^{-2}B=1} \atop {0.04^2A+0.04^{-2}B=2}} \right.[/tex]

[tex]\left \{ {{0.01A+100B=1} \atop {0.0016A+625B=2}} \right[/tex]

Whose solution by any method for solving 2x2 linear system of equations (elimination, reduction or substitution) is:

[tex]A=69.8\frac{bar}{m^6}\\\\ B=0.00302bar*m^6[/tex]

2. Now, for us to compute the work, we must first compute n, as the power relating the pressure and volume for this process:

[tex]P_1V_1^n=P_2V_2^n\\\\\frac{P_1}{P_2}=(\frac{V_2}{V_1} )^n\\\\\frac{1bar}{2bar}= (\frac{0.04m^3}{0.1m^3} )^n\\\\0.5=0.4^n\\\\n=\frac{ln(0.5)}{ln(0.4)} =0.7565[/tex]

Now, we compute the work:

[tex]W=\frac{P_2V_2-P_1V_1}{1-n} =\frac{2bar*0.04m^3-1bar*0.1m^3}{1-0.7565} \\\\W=-0.082bar*m^3*\frac{1x10^2kPa}{1bar}\\ \\W=-8.2kPa[/tex]

Regards.

Answer:

3 half-lives

Explanation:

The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.

Let's suppose we start with 64 g of the radioactive element.

Answer:

The absorption and strength of the H-beta lines change with the temperature of the stellar surface, and because of this, one can find the temperature of the star from their absorption lines and strength. To better comprehend, let us look into the concept of the atom's atomic structure.  

Atoms possess distinct energy levels and these levels of energy are constant, that is, the temperature has no influence on it. However, temperature possesses an influence on the electron numbers found within these levels of energy. Therefore, to generate an absorption line of hydrogen in the electromagnetic spectrum's visible band, the electrons are required to be present in the second energy level, that is when it captivates a photon.  

Therefore, after captivating the photons the electrons jump from level 2 to level 4, which shows that there is an increase in the stellar surface temperature and at the same time one can witness a decline in the strength of the H-beta lines. In case, if the temperature of the surface increases too much, then one will witness no attachment of electron with the hydrogen atom and thus no H lines, and if the temperature of the surface becomes too low, then the electrons will stay in the ground state and no formation of H lines will take place in that condition too.  

Hence, to generate a very robust H line, after captivating photons the majority of the electrons are required to stay in the second energy level.  

Answer:

[tex]M=1.1M[/tex]

Explanation:

Hello,

In this case, since we are mixing two NaOH solutions, the first step is to compute the total moles once the mixing is done, by using the volumes and concentrations of each solutions and subsequently adding them:

[tex]n_T=2.0L*0.60\frac{mol}{L}+495mL*\frac{1L}{1000mL}*3.0\frac{mol}{L}= 2.7molNaOH[/tex]

Next, we compute the total volume by adding the volume of each solution:

[tex]V_T=2.0L+495mL*\frac{1L}{1000mL}= 2.495L[/tex]

Finally, we compute the molarity of the resulting solution by the division between the total moles and the total volume:

[tex]M=\frac{2.7mol}{2.495L}\\ \\M=1.1M[/tex]

Best regards.

Answer:

0.001 M

Explanation:

The pH scale is used to determine the acidity or basicity of a solution.

The pH is related to the concentration of hydrogen ions through the following expression.

pH = -log [H⁺]

[H⁺] = antilog -pH = antilog - 3 = 0.001 M

Answer:

1/2 of the Pi

Explanation:

PV = nRT

we are going to assume the only things changing are pressure and number of mols, so we change the formula and substitute the variables to make it what we are looking for

[tex]\frac{Pi}{ni} = \frac{Pf}{nf}[/tex]

then we will assume Pi as 1 as it is not given, so we can state it easier

[tex]\frac{1atm}{10mol} = \frac{xatm}{5mol}[/tex]

then either cross multiply or just work it out to be

[tex]\frac{1}{2}[/tex] which we can say as "half of the initial pressure" as no number is given for initial pressure

Answer:

BaSO4(aq) + TiO(aq) —> BaO(aq) + TiSO4(aq)

Explanation

The equation for the reaction between barium sulfate and titanium (II) oxide is given below:

BaSO4 + TiO —>

In solution, the reactants will dissociates as follow:

BaSO4(aq) —> Ba^2+(aq) + SO4^2-(aq)

TiO(aq) —> Ti^2+(aq) + O^2-(aq)

The double displacement reaction will occur as follow:

Ba^2+(aq) + SO4^2-(aq) + Ti^2+(aq) + O^2-(aq) —> Ba^2+O^2-(aq) + Ti^2+SO4^2-(aq)

We can see that a double displacement reaction occurred as there is a double exchange of ions in the solution. The elemental equation is given below:

BaSO4(aq) + TiO(aq) —> BaO(aq) + TiSO4(aq)

Answer:

1.3×10⁻³ M

Explanation:

Hello,

In this case, given the dissociation reaction of acetic acid:

[tex]CH_3CO_2H(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + CH_3CO_2^-(aq)[/tex]

We can write the law of mass action for it:

[tex]Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}[/tex]

Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change [tex]x[/tex] due to the dissociation extent, we are able to rewrite it as shown below:

[tex]1.8x10^{-5}=\frac{x*x}{0.100-x}[/tex]

Thus, via the quadratic equation or solve, we obtain the following solutions:

[tex]x_1=-0.00135M\\x_2=0.00133M[/tex]

Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.

Regards.

Answer:

1.3×10^-3 M

Explanation:

Step 1:

Data obtained from the question:

Equilibrium constant (Ka) = 1.8×10^-5

Concentration of acetic acid, [CH3COOH] = 0.100 M

Concentration of hydronium ion, [H3O+] =..?

Step 2:

The balanced equation for the reaction.

CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq)

Step 3:

Determination of concentration of hydronium ion, [H3O+].

This can be obtained as follow:

Ka = [H3O+] [CH3CO2-] / [CH3CO2H]

Initial concentration:

[CH3COOH] = 0.100 M

[H3O+] = 0

[CH3CO2-] = 0

During reaction

[CH3COOH] = – y

[H3O+] = +y

[CH3CO2-] = +y

Equilibrium:

[CH3COOH] = 0.1 – y

[H3O+] = y

[CH3CO2-] = y

Ka = [H3O+] [CH3CO2-] / [CH3CO2H]

1.8×10^-5 = y × y / 0.1

Cross multiply

y^2 = 1.8×10^-5 x 0.1

Take the square root of both side

y = √(1.8×10^-5 x 0.1)

y = 1.3×10^-3 M

[H3O+] = y = 1.3×10^-3 M

Therefore, the concentration of the hydronium ion, [H3O+] is 1.3×10^-3 M

Answer:

(decreasing particle size) C

Explanation: That is one of the answers, if there are more I am sorry.

The given question is not complete, the complete question is:

A chemistry student needs 5.00 g of thiophene for an experiment. She has available 0.50 kg of a 28.7% w/w solution of thiophene in benzene, Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button Be sure your answer has the correct number of significant digits. X

Answer:

The correct answer is 17.4 grams.

Explanation:

As mentioned in the given question, 28.7 percent w/w solution thiophene in benzene shows that,  

(wt. of thiophene / wt. of thiopene + benzene) * 100 = 28.7

0.50 kg of the solution indicates that it is 500 grams of the solution.  

Therefore, the amount of thiophene found in the 500 grams of the solution is,  

500 g * 28.7 / 100 = 143.5 gm

Thus, 143.5 grams of thiophene is found 500 grams of the solution.  

Now, 1 gram of thiophene will be in 500/143.5 of solution.  

Therefore, 5 grams of thiophene will be in 500/143.5 * 5 g of the solution = 17.42 grams of the solution.  

Hence, the mass of the solution to be used by the student in the given case will be 17.4 grams.