Someone please help me

Answer:

ΔH = 46.2 kJ

Explanation:

Hello there!

In this case, according to the given set of reactions and the required one, it is possible to apply the Hess' rule in order to realize the following manipulations to obtain the required reaction:

1. Keep this reaction as it is.

2Fe(s) + O2(g) => 2FeO(s) ΔH = -545.6 kJ

2. Keep this reaction as it is.

4Fe(s) + 3O2(g) => 2Fe2O3(s) ΔH = -1,643.6 kJ

3. Reverse double this reaction so that we obtain:

2Fe3O4(s) => 6Fe(s) + 4O2(g) ΔH = -(-1,117.7 kJ)*2=2235.4kJ

Add them up to obtain:

2Fe(s) + O2(g) + 4Fe(s) + 3O2(g) + 2Fe3O4(s) => 6Fe(s) + 4O2(g) +2Fe2O3(s) + 2FeO(s)

Simplify common terms to obtain:

2 Fe3O4(s) => 2 Fe2O3(s) + 2 FeO(s)

Therefore, the enthalpy of such reaction is:

ΔH = 2235.4kJ -545.6 kJ -1,643.6 kJ

ΔH = 46.2 kJ

Best regards!

Answer:

B.) 14

Explanation:

27-13=14 neutrons

Answer: The theoretical yield of aspirin is 4.14 g

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]  [tex]\text{Moles of salicylic acid}=\frac{3.20g}{138.12g/mol}=0.023moles[/tex]

mass of acetic anhydride = [tex]density\times volume =1.082g/ml\times 3.71ml=4.01g[/tex]

[tex]\text{Moles of acetic anhydride}=\frac{4.01g}{102.04g/mol}=0.039moles[/tex]

[tex]C_9H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+C_2H_3O_2[/tex]  

According to stoichiometry :

1 mole of salycylic acid require 1 mole of acetic anhydride

Thus 0.023 moles of  salycylic acid require=[tex]\frac{1}{1}\times 0.023=0.023moles[/tex]  of acetic anhydride

Thus salycylic acid is the limiting reagent as it limits the formation of product and acetic anhydride is the excess reagent.

As 1 mole of salycylic give = 1 mole of aspirin

Thus 0.023 moles of salycylic acid give =[tex]\frac{1}{1}\times 0.023=0.023moles[/tex]  of aspirin

Mass of aspirin = [tex]moles\times {\text {Molar mass}}=0.023moles\times 180.15g/mol=4.14g[/tex]

Thus theoretical yield of aspirin is 4.14 g

Answer:

There are 2.85 x 10^22 atoms of carbon in a diamond with a mass of 0.568 g.

Hope this helps! :)

Answer:

True

Explanation:

Answer:

2

Explanation:

WO2(s) + 2H2(g) -> W(s) + 2H2O(l)

Answer:

d.7 is the correct answer

Answer:

36 atoms

Explanation:

The reactants are in the left side of the equation. First we determine how many atoms are there in the C₆H₁₂O₆ molecule:

There are two atoms in a O₂ molecule, and there are 6 O₂ molecules in the equation:

The total number of atoms in the reactants is

Answer:

The volume of reactant measured at STP left over is 409.9 L

Explanation:

Answer:

The answer is C if its wrong you can report my answer I'm 100% sure its C

Answer:

a. The condition that a reaction takes place without outside help Spontaneity

b. Difference of the enthalpy (of a system) minus the product of the entropy and absolute temperature Gibbs free energy

c. Sum of the internal energy plus the product of the pressure and volume for a reaction   Enthalpy.

d. The extent of randomness in a system Entropy

e. Solution in which no more solute can be dissolved in the solven Saturated solution

Explanation:

 (a) SPONTANEITY - The quality of being natural rather than planned in advance is described as spontaneity.

(b) GIBBS FREE ENERGY - Gibbs free energy, also known as the Gibbs function, Gibbs energy, or free enthalpy, is a quantity used to quantify the maximum amount of work that can be performed in a thermodynamic system when the temperature and pressure are held constant. The symbol ‘G' stands for Gibbs free energy.

(c) ENTHALPY - The heat absorbed or released during a process at constant pressure is equal to the Enthalpy shift. While “enthalpy” is often referred to as “heat content,” most people prefer to refer to it as “enthalpy.”

(d) ENTROPY - Entropy is the amount of thermal energy in a device per unit temperature that can't be used to do useful work. Since work is produced by ordered molecular motion, entropy is also a measure of a system's molecular disorder, or randomness. For several everyday phenomena, the idea of entropy offers profound insight into the direction of spontaneous change.

(e) SATURATED SOLUTION - A saturated solution is a chemical solution that contains the maximum amount of dissolved solute in the solvent. In a saturated solution, the extra solute will not dissolve. A number of factors influence the amount of solute that can be dissolved in a solvent to form a saturated solution.                              

Answer:

a. 969.1 R

b. 2237 ft/s

Explanation:

First the apparent specific heats are determined from the mass fractions of the gases:

[tex]c_{p} &=\left(\mathrm{mf} c_{p}\right)_{\mathrm{N}_{2}}+\left(\mathrm{mf} c_{p}\right) \mathrm{CO}_{2} \\ &=(0.65 \cdot 0.248+0.35 \cdot 0.203) \frac{\mathrm{Btu}}{\mathrm{lbm} \mathrm{R}} \\ &=0.232 \frac{\mathrm{Btu}}{\mathrm{lbmR}} \\ c_{v} &=\left(\mathrm{mf} c_{v}\right)_{\mathrm{N}_{2}}+\left(\mathrm{mf} c_{v}\right)_{\mathrm{CO}_{2}} \\ &=(0.65 \cdot 0.177+0.35 \cdot 0.158) \frac{\mathrm{Btu}}{\mathrm{lbmR}} \\ &=0.170 \frac{\mathrm{Btu}}{\mathrm{lbmR}}[/tex]

The isentropic coefficient then is:

[tex]k &=\frac{c_{p}}{c_{v}} \\ &=\frac{0.232}{0.17} \\ &=1.365[/tex]

The final temperature is determined from the isentropic nozzle efficiency relation:

[tex]T_{2} &=T_{1}-\eta_{N}\left(T_{1}-T_{2 s}\right) \\ &=T_{1}\left(1-\eta_{N}\left(1-\left(\frac{P_{2}}{P_{1}}\right)^{(k-1) / k}\right)\right) \\ &=1400\left(1-0.88\left(1-\left(\frac{800}{100}\right)^{(1.365-1) / 1.365}\right)\right) \mathrm{R} \\ &=969.1 \mathrm{R}[/tex]

b. The outlet velocity is determined from the energy balance:

[tex]h_{1} &+\frac{v_{1}^{2}}{2}=h_{2}+\frac{v_{2}^{2}}{2} \\ v_{2} &=\sqrt{2 c_{p}\left(T_{1}-T_{2}\right)} \\ &=\sqrt{2 \cdot 0.232(1400-969.2) \cdot 25037} \frac{\mathrm{ft}}{\mathrm{s}} \\ &=2237 \frac{\mathrm{ft}}{\mathrm{s}}[/tex]

Answer:

People are concerned with the rising level of carbon dioxide in the atmosphere because it could be leading to global warming, which is the observed increase of the Earth's temperatures. Engineers are working to rebalance the carbon cycle by designing appliances, buildings and homes that use less energy.

Explanation:

I don’t know if I’m right..........

Answer:

3-

Explanation:

Answer:

0.015M is the final molarity of the NaOH solution

Explanation:

A solution of 0.040M NaOH is diluted from 150mL to 250mL + 150mL = 400mL. That means the solution is diluted:

400mL / 150mL = 2.667 times.

As the original solution has a concentration of 0.040M, the diluted solution has a concentration of:

0.040M / 2.667 =

Answer:

Percentage yield = 23.8%

Explanation:

We'll begin by determining the limiting reactant. This can be obtained as follow:

Xe(g) + 2F₂(g) —> XeF₄

From the balanced equation above,

1 mole of Xe reacted with 2 moles of F₂.

Therefore, 2.2 moles of Xe will react with = 2.2 × 2 = 4.4 moles of F₂.

From the above calculation, we can see that a higher amount (i.e 4.4 moles) of F₂ than what was given (i.e 2.1 moles) is needed to react completely with 2.2 moles Xe.

Therefore, F₂ is the limiting reactant and Xe is the excess reactant.

Next, we shall determine the theoretical yield of XeF₄.

This can be obtained by using the limiting reactant as follow:

From the balanced equation above,

2 moles of F₂ reacted to produce 1 mole of XeF₄.

Therefore, 2.1 moles of F₂ will react to produce = (2.1 × 1)/2 = 1.05 moles of XeF₄.

Thus, the theoretical yield of XeF₄ is 1.05 moles.

Finally, we shall determine the percentage yield. This can be obtained as follow:

Actual yield of XeF₄ = 0.25 mole

Theoretical yield of XeF₄ = 1.05 moles

Percentage yield =?

Percentage yield = Actual yield / Theoretical yield × 100

Percentage yield = 0.25 / 1.05 × 100

Percentage yield = 0.238 × 100

Percentage yield = 23.8%

Answer:

HE

Explanation:

HE is a noble gas

Answer:

Aà bhûtÿ ñhjkjłfd hÿrèërqw

Explanation:

Answer:

B

Explanation:

I had same question

Answer:

slightly but poorly

Explanation:

it is a white crystalline solid that is practically insoluble in water and soluble in ether, chloroform, carbon disulfide, benzene, alcohol and acetone.

Answer:

3.30 gSiO2 / 60.085g SiO2 x 2 mol 0 / 1 mol SiO2 x (6.022*1023 ) = 6.61*1022 O atoms

Explanation:

Answer:

A via A P E X

The entity that would make ΔG to become negative at a given enthalpy and entropy is Changing the temperature (Option A)

ΔG = ΔH – TΔS

Where

NOTE

ΔG = +ve (non spontaneous)

ΔG = 0 (equilibrium)

ΔG = –ve (spontaneous)

From the Gibbs free energy equation, we can see that the entities that makes us the equation are

Thus, we can conclude that the correct answer to the question is: changing the temperature (Option A) since the equation has nothing to do with neither concentration, pressure nor volume

Learn more about Gibbs free energy:

https://brainly.com/question/9552459

#SPJ2

Answer:

from the chromosome..l dont know

Answer:

C. 1000

l think this is correct answer

l hope it's helpful for you

Answer:

There are 36 grams in 4.00 moles of Carbon.

Explanation:

In order to convert from moles of a substance into grams of the same substance, we need to use the substance's molar mass.

That means that in this case we use the molar mass of Carbon:

Thus, there are 36 grams in 4.00 moles of Carbon.

solid carbon dioxide, iodine, arsenic, and naphthalene

Explanation:

Examples of substances that undergo sublimation

Examples of solids that sublime are dry ice (solid carbon dioxide), iodine, arsenic, and naphthalene (the stuff mothballs are made of).

Answer:

9 moles

Explanation:

The balanced chemical equation provided in this question is as follows:

2CH₄ + S₈ → 2CS₂ + 4H₂S

In accordance to the above balanced equation, 1 mole of sulphur (S8) produces 4 moles of hydrogen sulfide (H2S).

Therefore, if 2.25mol of S8 is used, 2.25 × 4 = 9 mol

9 moles of H2S is produced.