What is the summary for Electrons and protons

For the chemical reaction below, determine the amount of hi produced when 3.35 g of hydrogen is reacted with 50.75 g of iodine t

ra1l [238]

Molar mass of H₂ = 1.008 × 2 g/mol = 2.016 g/mol 
Molar mass of I₂ = 126.9 × 2 g/mol = 253.8 g/mol 
Molar mass of HI = (1.008 + 126.9) g/mol = 127.9 g/mol

H₂(g) + I₂(g) → 2HI 
Mole ratio H₂ : I₂ : HI = 1 : 1 : 2 

Then the initial number of moles of H₂ = (3.35 g) / (2.016 g/mol) = 1.662 mol 
Initial number of moles of I₂ = (50.75 g) / (253.8 g/mol) = 0.2000 mol < 1.662 mol 
Hence, I₂ is the limiting reactant (limiting reagent). 

Number of moles of I₂ reacted = 0.2000 mol 
Number of moles of HI reacted = (0.2000 mol) × 2 = 0.4000 mol
Mass of HI reacted = (127.9 g/mol) × (0.4000 mol) = 51.16 g

8 0

4 years ago

Light with a wavelength range of 141–295 nm shines on a silicon surface in a photoelectric effect apparatus, and a reversing pot

Ksju [112]

Answer:

a) the longest wavelength of the light that will eject electrons from the silicon surface is 258.7891 nm

b) maximum kinetic energy will electrons reach the anode is 0.5098 eV

Explanation:

Given:

Wavelength range = 141-295 nm

Potential of 3.5 V

For the silicon, the work function is Φ = 4.8 eV = 7.68x10⁻¹⁹J

Questions:

a) What is the longest wavelength of the light that will eject electrons from the silicon surface, λ = ?

b) With what maximum kinetic energy will electrons reach the anode,

a) The longest wavelength that will eject electrons:

$\lambda =\frac{hc}{\phi }$

Here

h = Planck's constant = 6.625x10⁻³⁴J s

c = speed of light = 3x10⁸m/s

Substituting values:

$\lambda =\frac{6.625x10^{-34}*3x10^{8} }{7.68x10^{-19} } =2.588x10^{-7} m=258.7891nm$

b) The maximum kinetic energy (one electron):

$K=\frac{hc}{\lambda } -\phi =\frac{6.625x10^{-34}*3x10^{8} }{141x10^{-9} } -7.68x10^{-19} =6.416x10^{-19} J=4.0098eV$

Now, you need to calculate the potential difference:

$K'=eV$

Here

e = charge of electron = 1.6x10⁻¹⁹C

Substituting:

$K'=1.6x10^{-19} *3.5=5.6x10^{-19} J=3.5eV$

Now, the maximum kinetic energy of the electrons:

Kmax = 4.0098 - 3.5 = 0.5098 eV

6 0

4 years ago

Convert a density of 0.0045kg/cm3 to kg/m3

Alex

Answer:

4 500 kg/m3

Explanation:

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6 0

3 years ago

Look at the picture below. The boy is swinging back and forth on the swing. At which point is the potential energy of a swing th

Ilia_Sergeevich [38]

The potential energy of a swing is greatest at the top of the swing. (Point A).

5 0

3 years ago

Read 2 more answers

A 3.00 kg stone is dropped from a 39.2 m high building. when the stone has fallen 19.6 m, the magnitude of the impulse the earth

tatiyna

The formulas are, Impulse = mv-mu ....... (1) v^2 = u^2 + 2as .......... (2) We know that, u=0 a=acceleration=gravity = 9.80665 m/s^2 = 9.81 m/s^2 s=19.6 sub (2) we get, v^2 = 0+ 2*9.81*19.6 v^2 = 2*9.81*19.6 v^2 = 384.552 v = 19.6099 v = 19.61 m/s Sub v=19.61 m/s in (1) we get, Impulse = mv - mu we know that u=0; v= 19.61 m/s; m= 3.00 kg Impulse = 3(19.61) - 3(0) Impulse = 58.83-0 Impulse = 58.83 Ns. Therefore the gravitational force exerted by the stone is 58.83 Ns.

4 0

4 years ago

What is the summary for Electrons and protons​

What is the summary for Electrons and protons