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3 years ago

9

Calculate the number of molecules?

1 answer:

Ann [662]3 years ago

8 0

87.33 X 10^15 molecules

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The four lines observed in the visible emission spectrum of hydrogen tell us that: a. We could observe more lines if we had a st

Aliun [14]

Answer:

c. Only certain energies are allowed for the electron in a hydrogen atom

Explanation:

Emission spectrum are produced when the excited electron in a atom release the energy in the form of photons to come to ground state. These photons are of different wavelengths depending on the excitation state of emitting electron or transition of electron. These electromagnetic radiation are observed through prism to produce the spectrum.

As the name indicates this spectrum is produced by emission of energy. Although the electron can be excited by different methods such as by heating but the key point is that electrons in hydrogen atom will emit the photons of same energy which they absorb and each electron can absorb only certain type of energy. So four lines were observed in the visible spectrum of hydrogen because only certain energies are observed for hydrogen atom.

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3 years ago

The main purpose of the turbine in the turbojet engine is to A. drive the compressor. B. increase the velocity of the exhaust ga

Naddika [18.5K]

The main purpose of the turbine in the turbojet engine is to drive the compressor.

Answer: A) or the first option.

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4 years ago

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In some places there are deep cracks in earths crust called

Leona [35]

I think they are called Faults.

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3 years ago

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It is expected that a chemical reaction will occur when copper metal is combined with aqueous zinc sulfate. Explain why there wi

REY [17]

Answer:

$E_{cell}$ = +ve, reaction is spontaneous

$E_{cell}$ = -ve, reaction is non spontaneous

$E_{cell}$ = 0, reaction is in equilibrium

Case 1: when copper metal is combined with aqueous zinc sulfate.

$Cu+ZnSO_4\rightarrow Zn+CuSO_4$

Here copper is undergoing oxidation ad thus acts as anode and zinc is undergoing reduction , thus acts as cathode.

$E^o_{cell}$ = standard electrode potential = $E^0_{cathode}- E^0_{anode}$

Where both $E^0$ are standard reduction potentials.

$E^0_{[Cu^{2+}/Cu]}= +0.34V$

$E^0_{[Zn^{2+}/Zn]}= -0.76V$

$E^0=E^0_{[Zn^{2+}/Zn]}- E^0_{[Cu^{2+}/Cu]}$

$E^0=-0.76-(+0.34)=-1.10V$

Thus as $E_{cell}$ is negative , the reaction is non spontaneous.

Case 2: when zinc metal and aqueous copper sulfate solution are combined.

$Zn+CuSO_4\rightarrow Cu+ZnSO_4$

Here zinc is undergoing oxidation ad thus acts as anode and copper is undergoing reduction , thus acts as cathode.

$E^o_{cell}$ = standard electrode potential = $E^0_{cathode}- E^0_{anode}$

Where both $E^0$ are standard reduction potentials.

$E^0_{[Cu^{2+}/Cu]}= +0.34V$

$E^0_{[Zn^{2+}/Zn]}= -0.76V$

$E^0=E^0_{[Cu^{2+}/Cu]}- E^0_{[Zn^{2+}/Zn]}$

$E^0=+0.34-(-0.76)=+1.10V$

Thus as $E_{cell}$ is positive , the reaction is spontaneous.

3 0

4 years ago

I am a metal which can be drawn into thin wires

Gwar [14]

Answer:

Silver and copper

Explanation:

Siliver

Electrical conductivity=62000000(s/m)

Boiling point=2162

Melting point=961.78

Phase=solid

Copper

Electrical conductivity=59000000(s/m)

Boiling point =2927

Melting point=1084.62

Phase=soild

Metals like gold, silver and copper are drawn into thin wire and are used in an electric circuit because of their high electrical conductivity

Mostly Siliver and copper are used since using gold is much expensive.

3 0

3 years ago