Which sequence is an example of radioactive decay?

What is biodiversity?

kifflom [539]

Different amount of species in an area.

7 0

3 years ago

Whetes the most of the mass of our solar system today

Simora [160]

Planets, black wholes gravity

3 0

3 years ago

A chemical plant produces ammonia using the following reaction at a very high temperature and pressure. Which design issue is mo

Lorico [155]

Answer:

D. The equipment needed to accommodate the high temperature and pressure will be expensive to produce.

Explanation:

Hello!

In this case, for the considered reaction, it is clear it is an exothermic reaction because it produces energy; and therefore, the higher the temperature the more reactants are yielded as the reverse reaction is favored. Moreover, since the effect of pressure is verified as favoring the side with fewer moles; in this case the products side (2 moles of ammonia).

In such a way, the high pressure favors the formation of ammonia whereas the high temperature the formation of hydrogen and nitrogen and therefore, option A is ruled out. Since the high pressure shifts the reaction rightwards and the high temperature leftwards, we would not be able to know whether the reaction has ended or not because it will be a "go and come back" process, that is why B is also discarded. Now, since hydrogen and nitrogen would be the "wastes", we discard C because they are not toxic. That is why the most accurate answer would be D. because it is actually true that such equipment is quite expensive.

Best regards!

6 0

3 years ago

A helium-filled balloon at 310.0 K and 1 atm, contains 0.05 g He, and has a volume of 1.21 L. It is placed in a freezer (T = 235

trapecia [35]

Answer : The value of $\Delta E$ of the gas is 2.79 Joules.

Explanation :

First we have to calculate the moles of helium.

$\text{Moles of helium}=\frac{\text{Mass of helium}}{\text{Molar mass of helium}}$

Molar mass of helium = 4 g/mole

$\text{Moles of helium}=\frac{0.05g}{4g/mole}=0.0125mole$

Now we have to calculate the heat.

Formula used :

$q=nc_p\Delta T\\\\q=nc_p(T_2-T_1)$

where,

q = heat

n = number of moles of helium gas = 0.0125 mole

$c_p$ = specific heat of helium = 20.8 J/mol.K

$T_1$ = initial temperature = 310.0 K

$T_2$ = final temperature = 235.0 K

Now put all the given values in the above formula, we get:

$q=nc_p(T_2-T_1)$

$q=(0.0125mole)\times (20.8J/mol.K)\times (235.0-310.0)K$

$q=-19.5J$

Now we have top calculate the work done.

Formula used :

$w=-p\Delta V\\\\w=-p(V_2-V_1)$

where,

w = work done

p = pressure of the gas = 1 atm

$V_1$ = initial volume = 1.21 L

$V_2$ = final volume = 0.99 L

Now put all the given values in the above formula, we get:

$w=-p(V_2-V_1)$

$w=-(1atm)\times (0.99-1.21)L$

$w=0.22L.artm=0.22\times 101.3J=22.29J$

conversion used : (1 L.atm = 101.3 J)

Now we have to calculate the value of $\Delta E$ of the gas.

$\Delta E=q+w$

$\Delta E=(-19.5J)+22.29J$

$\Delta E=2.79J$

Therefore, the value of $\Delta E$ of the gas is 2.79 Joules.

3 0

3 years ago

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.

6 0

3 years ago