How many protons are in the nucleus of this atom? What is the mass number of this atom?

Calculate the equilibrium number of vacancies per cubic meter for copper at 1000K. The energy for vacancy formation is 0.9eV/ato

nexus9112 [7]

Answer:

Therefore the equilibrium number of vacancies per unit cubic meter =2.34×10²⁴ vacancies/ mole

Explanation:

The equilibrium number of of vacancies is denoted by $N_v$ .

It is depends on

total no. of atomic number(N)
energy required for vacancy
Boltzmann's constant (k)= 8.62×10⁻⁵ev K⁻¹
temperature (T).

$N_v=Ne^{-\frac{Q_v}{kT} }$

To find equilibrium number of of vacancies we have find N.

$N=\frac{N_A\ \rho}{A_{cu}}$

Here ρ= 8.45 g/cm³ =8.45 ×10⁶m³

$N_A$ = Avogadro Number = 6.023×10²³

$A_{Cu}$ = 63.5 g/mole

$N=\frac{6.023\times 10^{23}\times 8.45\times 10^{6}}{63.5}$

$=8.01\times 10^{28$ g/mole

Here $Q_v$ =0.9 ev/atom , T= 1000k

Therefore the equilibrium number of vacancies per unit cubic meter,

$N_v=( 8.01\times 10^{28}) e^{-(\frac{0.9}{8.62\times10^{-5}\times 1000})$

=2.34×10²⁴ vacancies/ mole

3 0

3 years ago

The universe cooled after the Big Bang. At some point, hydrogen atoms combined to form helium. What is this process called?

Lunna [17]

A) nuclear fusion is the answer

6 0

3 years ago

Read 2 more answers

Where the oxygen comes from the air (21% O2 and 79% N2). If oxygen is fed from air in excess of the stoichiometric amount requir

guajiro [1.7K]

Answer:

$y_{O2} =4.3$ %

Explanation:

The ethanol combustion reaction is:

$C_{2}H_{5} OH+3O_{2}$ → $2CO_{2}+3H_{2}O$

If we had the amount (x moles) of ethanol, we would calculate the oxygen moles required:

$x*1.10(excess)*\frac{3 O_{2}moles }{etOHmole}$

Dividing the previous equation by x:

$1.10(excess)*\frac{3 O_{2}moles}{etOHmole}=3.30\frac{O_{2}moles}{etOHmole}$

We would need 3.30 oxygen moles per ethanol mole.

Then we apply the composition relation between O2 and N2 in the feed air:

$3.30(O_{2} moles)*\frac{0.79(N_{2} moles)}{0.21(O_{2} moles)}=121.414 (N_{2} moles )$

Then calculate the oxygen moles number leaving the reactor, considering that 0.85 ethanol moles react and the stoichiometry of the reaction:

$3.30(O_{2} moles)-0.85(etOHmoles)*\frac{3(O_{2} moles)}{1(etOHmoles)} =0.75O_{2} moles$

Calculate the number of moles of CO2 and water considering the same:

$0.85(etOHmoles)*\frac{3(H_{2}Omoles)}{1(etOHmoles)}=2.55(H_{2}Omoles)$

$0.85(etOHmoles)*\frac{2(CO_{2}moles)}{1(etOHmoles)}=1.7(CO_{2}moles)$

The total number of moles at the reactor output would be:

$N=1.7(CO2)+12.414(N2)+2.55(H2O)+0.75(O2)\\ N=17.414(Dry-air-moles)$

So, the oxygen mole fraction would be:

$y_{O_{2}}=\frac{0.75}{17.414}=0.0430=4.3$ %

6 0

3 years ago

A topographical map would be useful for which activity? A. planning a hiking trip B. studying plant growth over time C. studying

amm1812

The answer is A. planning a hiking trip

A topographical map would not help studying plant growth over time unless you are looking for a better altitude to plant said plants.

A topographical map would not help studying rainfall for one year unless your location was really so high or low that it affected your weather

And most of all, a topographical map would not be useful for planning a cuise across the Atlantic Ocean because the elevation of the sea is zero!

A topographical map would be useful for planning a hiking trip because there are many factors and details that a hike should have. Which includes height, distance, paths, and elevation.

5 0

3 years ago

What is the valency of CH3COO

WINSTONCH [101]

Answer:

thats too hard sorry

Explanation:

6 0

3 years ago