By examining data from distant stars, astronomers can determine
if a star is moving away from or toward Earth. Which of the
following pieces of data would be most helpful in determining
the motion of a star?
A The star gives off blue-white light.
B
The star gives off mainly radio waves and X-rays.
C
The light spectrum given off by the star is shifted toward the
red end.
.
D
The surface temperature of the star is approximately 10,000°
Celsius.

Answer: At equilibrium , there are 0.274 moles of [tex]Br_2[/tex]

Explanation:

Moles of  [tex]H_2[/tex] = 0.682 mole

Moles of  [tex]Br_2[/tex] = 0.440 mole

Volume of solution = 2.00 L

Initial concentration of [tex]H_2[/tex] = [tex]\frac{0.682}{2.00}=0.341 M[/tex]

Initial concentration of [tex]Br_2[/tex] =  [tex]\frac{0.440}{2.00}=0.220 M[/tex]

Equilibrium concentration of [tex]H_2[/tex] = [tex]\frac{0.516}{2.00}=0.258 M[/tex]

The given balanced equilibrium reaction is,

             [tex]H_2(g)+Br_2(g)\rightleftharpoons 2HBr(g)[/tex]

Initial conc.   0.341 M    0.220 M        0 M    

At eqm. conc.   (0.341-x) M   (0.220-x) M   (2x) M

Given : (0.341-x) M = 0.258 M

x= 0.083 M

Thus equilibrium concentartion of [tex]Br_2[/tex] = (0.220-0.083) M = 0.137 M

Thus moles of [tex]Br_2[/tex] at equilibrium = [tex]0.137M\times 2.00L=0.274mol[/tex]

At equilibrium , there are 0.274 moles of [tex]Br_2[/tex]

Answer:

True

Explanation:

Hydrogen bonding is a bond that exists between hydrogen and a highly electronegative element such as oxygen, nitrogen, fluorine etc.

The greater solubility of the triphenylphosphine oxide owes to the hydrogen bonded interaction between it and the 1-propanol.

The alkene lacks such hydrogen bonded interaction because it does not have a highly electronegative atom in its structure.

Hence, triphenylphosphine oxide is removed based on its polarity and hydrogen bonding ability.

Answer:

We can simply refer to the cation in the ionic compound as magnesium. Phosphorus, Pstart text, P, end text, is a group 15 element and therefore forms 3- anions.

Explanation:

Because it is an anion, we add the suffix -ide to its name to get phosphide as the name of the ion.

Answer:

1 km an hour

Explanation:

i mean its pretty easy like you said if at 4 hours its traveled 4 km then its going 1 km an hour and at 10 its gone 10 km

Answer:

Al,Ga,B

Explanation:

Now since i helped you can you help me with this plz

Matteo took 5 math quizzes. The mean of the 5 quizzes was 8.2. Here are four of his quiz scores 7, 7, 8, 10. What is the 5th quiz score? Show work.

Boron ( B )

Aluminium ( Al )

Gallium ( Ga )

Answer:

Objects appear different colours because they absorb some colours (wavelengths) and reflected or transmit other colours. ... For example, a red shirt looks red because the dye molecules in the fabric have absorbed the wavelengths of light from the violet/blue end of the spectrum

A red object appear red because it absorbs light of wavelengths other than red. Therefore, option C is correct.

The distance between identical points (adjacent crests) in adjacent cycles of a waveform signal propagated in space or along a wire is defined as the wavelength. This length is typically specified in wireless systems in meters (m), centimeters (cm), or millimeters (mm) (mm).

A transverse wave's wavelength is defined as the distance between two adjacent crests. A longitudinal wave's wavelength can be calculated as the distance between two adjacent compressions.

The wavelengths that are reflected or transmitted are what we see as colors. A red shirt, for example, appears red because the dye molecules in the fabric have absorbed light wavelengths from the violet/blue end of the spectrum. The only light reflected from the shirt is red light.

Thus, option C is correct.

To learn more about the wavelength, follow the link;

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Answer:

Helium and hydrogen......

Answer:

The correct answer is - 1 and 3 are true.

Explanation:

Hydrogen bonds require a lot of energy to be broken as these bonds are relatively strong intermolecular forces which makes the boiling point of liquid like water very high, as it requires a lot of heat to break the intermolecular bonds holding the water molecules together.

An increase in the surface area of the liquid also increases the rate of evaporation as it takes place among the molecules of the liquid on the surface.

Answer:

NO is the limiting reagent.  

In this reaction 0.886 mole of NO2 is produced

Explanation:

The chemical equation for this reaction is  

2NO(g) + O2(g) → 2NO2(g)

In this limiting reagent reaction, 2 moles of NO reacts with one mole of O2  to produce 2 mole of 2NO2

0.886 mole of NO * (2 mole of NO2/2 mole of NO) = 0.886 mole of NO2

0.503 mole of O2 * (1 mole of NO2/1 mole of O2) = 1.01 mole of NO2

Hence, NO is the limiting reagent.  

In this reaction 0.886 mole of NO2 is produced

Answer:

True

Explanation:

All metals do rust but at different rates. Gold, platinum, and silver can rust if but at different rates. It can take time for it to rust, if you clean your metals, it won't rust, it'll take awhile before it rusts if you keep cleaning them.

Hopefully this helps :3 sorry if wrong :( plz mark brainiest if correct :D your bootiful/handsome! Have a great day luv <3

-Bee~

Answer:There is a iin dipole attraction between two hydrogen atom

Explanation:

The same atoms have the ion dipole attraction between them the same atoms repel each other

Answer:

The answer is agriculture.

Explanation:

Answer: Agriculture

Explanation:

I got it right on my exam

Answer:

A. non renewable energy sources cannot be used over again and renewable energy sources can be used again

Answer:

A. Nonrenewable energy sources cannot be used over again. Renewable energy sources can be used again.

Explanation:

Answer:

0.3857 litres is the answer

Answer:

here you are

Explanation:

atomic energy

Answer:

The real volume of the gas particles is extremely small when compared to the entire volume of their container.

d)Gas particles constantly expand and contract, which constantly alters their volume. When these volumes are averaged, a value of zero is obtained

Explanation:

potassium chloride from potassium hydroxide and hydrochloric acid

Answer: Sublimation

Explanation:

Sublimation : It is a process in which a solid directly changes to gaseous phase by providing heat.

Freezing is a process in which a liquid changes into solid phase when allowed to cool.

Condensation is a process in which a gas changes into liquid phase when allowed to cool.

 Deposition is a  process in which a gas deposits as solid phase when allowed to cool.

Thus change of state where energy is absorbed is sublimation.

Answer:

85.952 ml [tex]Zn^2^+[/tex]  needed to titrate the excess complexing reagent .

Explanation:

Lets calculate

After addition of 80 ml of EDTA the solution becomes = 20 + 70 = 90 ml

As the number of moles of [tex]CoSO_4[/tex] =[tex]\frac{Given mass }{molar mass}[/tex]

                                                       =[tex]\frac{1.817}{155}[/tex]

                                                          =0.01172

Molarity = [tex]\frac{no. of moles}{volume of solution}[/tex]

           =[tex]\frac{0.01172}{20}[/tex]

        =0.000586 moles

Excess of EDTA = concentration of EDTA - concentration of CoSO4

                            = 0.009005 - 0.000586

                           = 0.008419 M

As M1V1 ( Excess of EDTA ) = M2V2 [tex](Zn^2^+)[/tex]

           [tex]0.008419\times100ml=0.009795\times V2[/tex]

           [tex]V2=\frac{0.008419\times100}{0.009795}[/tex]

             V2 =85.952 ml

Therefore , 85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .

Answer:

2.87 gram

N2 is the limiting agent

Explanation:

We will find out if there is sufficient N2 and h2 to produce NH3

a) For 2.36 grams of N2

Molar mass of N2 = 28.02

Number of moles of N2 in 2.36 grams = 2.36/28.02

Mass of NH3 = 17.034 g

Now NH3 produced form 2.36 grams of N2 =  

2.36/28.02 * 2 * 17.034 = 2.87 g NH3

b) For 1.52 g of H2  

NH3 produced = 1.52/2.016 * (2/3) * 17.034 = 8.56

N2 Is not enough to produce 2.87 g of NH3 and also H2 is not enough to make 8.56 g of NH3.  

N2 is the limiting agent as it has smaller product mass

Answer:

Explanation:

The equation we use to calculate the volume needed to prepare other [tex](C_1,V_1)[/tex] the solution that has a concentration [tex]C_2[/tex]  and volume [tex]V_2[/tex]  is:

[tex]C_1V_1 =C_2V_2[/tex]

[tex]V_1=\dfrac{C_2V_2}{C_1}[/tex]

where;

[tex]C_1[/tex]= concentration of the first solution

[tex]V_1[/tex] = volume of the first solution

[tex]C_2[/tex] = concentration of the second solution

[tex]V_2[/tex] = volume of the second solution

2) Reduction half cell reaction for the copper (II) ion is:

[tex]Cu^{2+} + 2e^- \to Cu[/tex]

3) [tex]Cu^{+2} + 2e^- \to Cu \text{ \ \ \ E = 0.3370}[/tex]

[tex]Zn^{+2} + 2 e^- \to Zn \ \ \ \ \ \ E = -0.763[/tex]

[tex]Zn \to Zn^{+2} + 2 e^- \ \ \ \ \ \ E = +0.763[/tex]

Since the reduction potential of Cu is more; it means copper will go into reduction and zinc will undergo oxidation.

Standard Potential =[tex]E^0_{left} - E^0_{right}[/tex]

[tex]= -0.763 -0.337[/tex]  ( since both are reduction potential)

[tex]\mathbf{E^0_{cell} = -1.100 volt}[/tex]

Answer:

[tex]T_2=637\°C[/tex]

Explanation:

Hello there!

In this case, considering this problem as pressure constant, since the change is exhibited in temperature and volume only, it is possible for us to use the Charles' law as shown below:

[tex]\frac{V_2}{T_2}=\frac{V_1}{T_1}[/tex]

Thus, by solving for the final temperature, we obtain:

[tex]T_2=\frac{T_1V_2}{V_1}\\\\T_2=\frac{273K*1L}{0.30L}\\\\T_2=910K-273\\\\T_2=637\°C[/tex]

Best regards!

Answer:

[tex]74.5gCO_2[/tex]

Explanation:

Hello there!

In this case, for the described reaction, it is possible to realize there is a 13:8 mole ratio between oxygen (O2) and carbon dioxide (CO2); moreover, since the molar mass of the former is 32.00 g/mol and that of latter is 44.01 g/mol, the produced mass of the required product turns out to be:

[tex]88gO_2*\frac{1molO_2}{32.00gO_2}*\frac{8molCO_2}{13molO_2}*\frac{44.01gCO_2}{1molCO_2} \\\\=74.5gCO_2[/tex]

Best regards!

Answer: The percent yield of the reaction is 83.5 %

Explanation:

The given balanced equation is

[tex]SiO_2+3C\rightarrow SiC+2CO[/tex]

[tex]SiO_2[/tex] is the limiting reagent as it limits the formation of product and [tex]C[/tex] is the excess reagent.

According to stoichiometry :

60.08 g of [tex]SiO_2[/tex] produce = 40.11 of [tex]SiC[/tex]

Thus 50.0 of [tex]SiO_2[/tex] will produce=[tex]\frac{40.11}{60.08}\times 50.0=33.4[/tex]  of [tex]SiC[/tex]

 Experimental yield of SiC = 27.9 g

Percent yield = [tex]\frac{\text {Experimental yield}}{\text {theoretical yield}}\times 100=\frac{27.9g}{33.4g}\times 100=83.5\%[/tex]

Thus  percent yield of the reaction is 83.5 %

The percent yield of 83.5 % of 50.0 g of silicon dioxide is heated with an excess of carbon, and 27.9 g of silicon carbide is produced in the reaction.

The chemical equations are balanced when the reactants react to form products. The reactants and products react in proper ratios and if they are not in ratio then we balance them by adding the required quantity in the reactants and the products.

The given balanced equation is

[tex]\rm SiO_2+3C---- > SiC+2CO[/tex]

[tex]SiO_2[/tex] is the limiting reagent as it limits the formation of product and is the excess reagent.

According to stoichiometry

60.08 g [tex]SiO_2[/tex] of  produce = 40.11 of [tex]SiC[/tex]

Thus 50.0 of  [tex]SiO_2[/tex] will produce=  [tex]\dfrac{40.11}{60.08} \times 50=33.4\ SiC[/tex]

The experimental yield of SiC = 27.9 g

The percentage yield will be calculated as

[tex]\rm Percentage \ Yield = \frac{Experimental\ yield}{Theoretical \ yield }\times 100[/tex]

[tex]\rm Percentage \ yield =\dfrac{27.9}{33.49} \times 100=83.5[/tex]

Thus the percent yield of 83.5 % of 50.0 g of silicon dioxide is heated with an excess of carbon, and 27.9 g of silicon carbide is produced in the reaction.

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Answer:

221.22K or -51°C

Explanation:

We will be using the Ideal Gas Law to calculate the temperature of the gas. It is a mathematical relationship that describes the behavior of ideal gas ample for any combo of varying pressure, volume, temperature, and # of moles (n). It is derived by combing Boyle's Law, Charles' Law, Gay-Lussac's & Avogadro's Law.

Note: As always, remember that temperature must be in Kelvin not Celsius when using this equation.

Ideal Gas Law: [tex]PV = nRT[/tex], where P = pressure, V = volume (in Liters), n = # of moles, R = the ideal gas constant, and T = temperature (in Kelvin).

Based on the problem, we are given the pressure, volume, and # of moles. We are asked to find the temperature. What about R you ask? Well, R is a constant that is the value of 1 mole of gas at STP. R has various values depending on the pressure units. In this case, our pressure is in atm so the R value = 0.0821.

Onto the math - all that needs to be done now is to plug and chug. Plug in the given values to find the temperature:

Set up: [tex](7.6 atm)(12L) = (5 mol)(0.0821 L*atm/(mol*K))(T)[/tex]

==> [tex]T = \frac{(7.6 atm)(12L)}{(5 mol)(0.0821 L*atm/(mol*K))}[/tex]

==> T = 221.17K

The answer is 221.17K. To convert into Celsius, subtract by 273.15 to get -50.99 or -51°C.

Answer:

Phenol is more acidic than alcohol due to resonance stabilization of the phenoxide ion.

Answer:

The correct approach is "1 M".

Explanation:

The given values are:

Volume of HCL,

V₁ = 45 ml

In prepared solution,

V₂ = 15 ml

Concentration,

C₁ = ?

C₂ = 3.0 M

As we know,

⇒  [tex]V_1C_1=V_2C_2[/tex]

or,

⇒      [tex]C_1=\frac{V_2C_2}{V_1}[/tex]

On substituting the values, we get

⇒           [tex]=\frac{15\times 3}{45}[/tex]

⇒           [tex]=\frac{45}{45}[/tex]

⇒           [tex]=1 \ M[/tex]

Answer & Explanation:

Gamma rays are the most energetic form of electromagnetic radiation. By observing the distant galaxy at gamma-rays, scientists can search for new physics, test theories, and perform experiments that are not possible in earth-bound laboratories.