Someone can help me please??

This problem is providing us with the enthalpy of formation of Fe2O3 (s) and the enthalpy of reaction when it reacts with Al to form Al2O3 (s) and Fe. Thus, the enthalpy of formation of Al2O3 (s) is required and found to be -1675.7 kJ/mol as follows.

In chemistry, the heat involved in a chemical process can be quantified via the difference in the overall enthalpy of products minus that of reactants:

[tex]\Delta H_r=\Delta H_{products}-\Delta H_{reactants}[/tex]

Now, with the given reaction:

[tex]Fe_2O_3 (s) + 2 Al (s) \rightarrow 2 Fe (s) + Al_2O_3 (s)[/tex]

One can see both Al and Fe have zero as their enthalpies of formation for they are elements. In such a way, one can rearrange the previous formula as:

[tex]\Delta H_r=\Delta H_{Al_2O_3}-\Delta H_{Fe_2O_3}[/tex]

And hence plug in the given energies in order to find the required:

[tex]-851.5kJ/mol=\Delta H_{Al_2O_3}-(-824.2kJ/mol)\\\\\Delta H_{Al_2O_3}=-851.5kJ/mol+(-824.2kJ/mol)\\\\\Delta H_{Al_2O_3}=-1675.7kJ/mol[/tex]

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Answer: For ionic compounds, the ratio in which. positive & negative ions combine is ratio that achieves charge neutrality for resulting compound.

Explanation:

Answer:

Explanation:

Determining the Limiting Reagent

One reactant (A) is chosen, and the balanced chemical equation is used to determine the amount of the other reactant (B) necessary to react with A. If the amount of B actually present exceeds the amount required, then B is in excess, and A is the limiting reagent.

Answer:From this you can see that 5 moles of hydrogen gas would react with 2.5 of the available 3 moles of oxygen gas, to form 5 moles of water.

Explanation:

This problem is providing the rate of the given reaction as 0.840 M/s and asks for the relative rate of change of each species. At the end, the results turned out to be -0.840 M/s, 0.210 M/s and 0.420 M/s for A, B and C respectively.

In chemical kinetics, when chemical reactions take place, it turns out possible for us to quantify in what extent a reaction is proceeding over time, by overseeing the change in the concentration as the time goes by.

In such a way, when given the rate of reaction, one can calculate the relative rate of change of each species by using the following equation, involving their stoichiometric coefficients in the reaction:

[tex]r_A=\frac{r}{-1} \\\\r_B=\frac{r}{-4} \\\\r_C=\frac{r}{2}[/tex]

Where these coefficients are negative for reactants and positive for products. In such a way, one can plug in the given rate of reaction to obtain each species' as follows:

[tex]r_A=\frac{0.840M/s}{-1} =-0.840M/s\\\\r_B=\frac{0.840M/s}{-4} =0.210M/s\\\\r_C=\frac{0.840M/s}{2}=0.420M/s[/tex]

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Answer:

covalent bond

Explanation:

a covalent bond happens between two nonmetals

a ionic bond happens between a metal and a non metal

CO2 is a bond between carbon and oxygen

carbon and oxygen are both non metals therefore CO2 is a covalent bond

Answer:

High pressure and low pressure have two distinct types of weather associated with them...typically. High pressure often means dry weather with sunshine. Low pressure often means clouds and precipitation. High pressure is associated with sinking air.

Explanation:

High-pressure systems are usually called Fair Weather Systems because the 7 types of weather in a high-pressure zone are generally comfortable and clear. Keep in mind that high and low pressures mean the air is under higher or lower pressure relative to the surrounding air.

This problem is providing the initial volume and pressure of a gas in an engine cylinder and asks for the final pressure once the volume of the gas has decreased due to a compression. At the end, the result turns out to be 11.7 atm.

In chemistry, gas laws allow us to calculate pressure, volume, temperature or moles depending on a specified change and based on the concept and equation of the ideal gas, which derives the well-known gas laws; Boyle's, Charles', Gay-Lussac's and Avogadro's.

Thus, since this problem provides initial and final volume and initial pressure for us to calculate the final pressure, we understand we need to apply the Boyle's law as a directly proportional relationship between these two:

[tex]P_1V_1=P_2V_2[/tex]

Thus, we solve for the final pressure, P2, to get:

[tex]P_2=\frac{P_1V_1}{V_2}=\frac{1.0atm*175mL}{15mL}\\ \\ P_2=11.7atm[/tex]

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Answer:

The answer is true

Explanation:

the ovary is a tubular structure and contains ovules

[tex]\bold{\huge{\pink{\underline{ Answer }}}}[/tex]

Here, we will use the concept of planks quantum theory .

According to planks quantum theory :-

Here,

We have to calculate the energy of an X photon

According to the planks quantum theory of radiation :-

[tex]\bold{\pink{ E = hv }}[/tex]

[tex]\sf{ E = h}{\sf{\times{\dfrac{c}{λ}}}}[/tex]

Subsitute the required values,

[tex]\sf{ E = 6.626 × 10^{-34} }{\sf{\times{\dfrac{3 × 10^{8}}{5 × 10^{-10}}}}}[/tex]

[tex]\sf{ E = }{\sf{\dfrac{19.87× 10^{-26}}{5 × 10^{-10}}}}[/tex]

[tex]\sf{ E = 3.974 × 10^{-36}}[/tex]

Hence, The energy of an X ray photon is 3.974 × 10^-36

We have ,

According to the planks quantum theory,

[tex]\bold{\pink{ E = hv }}[/tex]

Subsitute the required values,

[tex]\sf{ E = 6.626 × 10^{-34}× 4.57 × 10^{14}}[/tex]

[tex]\sf{ E = 30.28 × 10^{- 20}}[/tex]

[tex]\sf{ E = 3.028 × 10^{ - 19}}[/tex]

Hence, The energy related to an electron occupying the ground state of hydrogen atoms is 3.028 × 10^-19

We have ,

We know that,

[tex]\bold{\pink{ v = }}{\bold{\pink{\dfrac{ c }{λ}}}}[/tex]

[tex]\sf{ λ = }{\sf{\dfrac{ c }{v}}}[/tex]

Subsitute the required values,

[tex]\sf{ λ = }{\sf{\dfrac{ 3 × 10^{8} }{4.6 × 10^{-14}}}}[/tex]

[tex]\sf{ λ = 0.65 × 10^{22}}[/tex]

Hence, The of this light is 0.65 × 10^22 .

[ Note :- Kindly refer answer in the app]

Answer:

648

Explanation:

what you're going to do your first is to convert the 192g to number of atoms

firstly you are going to convert 192 to moles using the formula reacting mass all over molar mass, into it that you're going to get 12 as your answer, you Dey multiply the 12 to avocados constant

in doing that you have I've gotten the number of atoms present in 192 g of oxygen

Answer:

what you need to do is,

you take the relative atomic mass of each element and multiply it by the no of atoms it has. do this for all the elements present, and add the values. that's it!

Explanation:

try to do the last one by yourself, it is easy and you will be using the molecular/formula mass mostly everywhere in chemistry.

Answer:

I used a picture

Explanation:

Hope it helps<3

Answer:

Calculate the volume (in mL) of the 1.356 M stock NaOH solution needed to prepare 250.0 mL ... Glucose (molar mass=180.16 g/mol) is a simple, soluble sugar ... g of glucose in enough water to make 500.0 mL of solution. • Step 2: Transfer 18.6 mL of the

Explanation:

Answer:

29.9g please refer to the picture for work

Answer: Your gut bacteria can affect how your food is digested, how fat is stored and whether you feel hungry or full.

Explanation: Thus, a healthy gut bacteria may be important for maintaining a healthy weight. High-fiber foods like whole grains, fruits, vegetables, nuts and seeds can all promote healthy gut bacteria.

Answer:

Consider the following reaction where Kc = 1.29×10-2 at 600 K:

COCl2(g) <=> CO(g) + Cl2(g)

A reaction mixture was found to contain 9.85×10-2 moles of COCl2(g), 2.61×10-2moles of CO(g), and 3.71×10-2 moles of Cl2(g), in a 1.00 Liter container.

Indicated true (T) or false (F) for each of the following:

Answer:

The water particles move in an upward motion through the wave.

Explanation:

When water particles become part of a wave they start to move up or down.

Answer:

u deleted my answer before so

Explanation:

Answer:

1. combustion

2. decomposition

3. decomposition

4. combination

5. decomposition

6. decomposition

Explanation:

combination of a reaction is when 2 more or elements/ compounds combine to form a compound. example: (A+B→AB)

decomposition of a reaction is when a chemical breakdown. example: (AB→A+B)

a combustion reaction is when an element/ compound reacts with oxygen to form the product of water and carbon dioxide.

example: ( [tex]C_{x}[/tex] [tex]H_{y}[/tex] + [tex]O_{2}[/tex] → [tex]H_{2}[/tex]O + [tex]CO_{2}[/tex] )

Here, we need to solve this problem using Ideal gas law ( PV=nRT).

Where –

Now, according to the question –

Calculation –

[tex]\qquad[/tex] [tex]\pink{\twoheadrightarrow\bf PV = nRT}[/tex]

[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n = \dfrac{PV}{RT}[/tex]

[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n = \dfrac{ 2.2 \: \:\times 58 \: } {0.0821 \times 313}[/tex]

[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n = \dfrac{ 2.2 \times 58}{0.0821 \times 313} [/tex]

[tex]\qquad[/tex] [tex]\twoheadrightarrow\sf n =\dfrac{127.6}{25.7}[/tex]

[tex]\qquad[/tex] [tex]\pink{\twoheadrightarrow\bf n = 4.9656 \: moles }[/tex]

_______________________________________

Given Information ,

We have to find the number of moles .

We use here " Ideal Gas Equation" which is

where

n is number of moles

R is universal gas Constant

T is temperature

P is pressure

V is volume

On substituting the value we get

➣ 2.2 × 58 = n × 0.0821 × 313

➣ 127.6 = n × 25.70

➣ 127.6/25.70 = n

➣ 4.96 = n

➣ 5 ≈ n

So, the number of moles are 5 .

Considering the definition of molarity, 0.4375 moles of iron(II) nitrite you would recover.

In order to find the moles of the solid that can be recovered from this solution, you need to use the definition of molarity.

Molar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:

[tex]Molarity=\frac{number of moles}{volume}[/tex]

Molarity is expressed in units [tex]\frac{moles}{liters}[/tex].

Moles of iron(II) nitrite

In this case, you evaporated 125 mL of a 3.5 M solution of iron(II) nitrite​. Then you know:

Replacing in the definition of molarity:

[tex]3.5 M=\frac{number of moles}{0.125 L}[/tex]

Solving:

number of moles= 3.5 M× 0.125 L

number of moles= 0.4375 moles

Finally, 0.4375 moles of iron(II) nitrite you would recover.

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Answer:

4-methly-2-pentyne

Explanation:

Answer:

Explanation:

Properties of Metal

1. Metals are ductile. ...

2. Metals are a good conductor of heat and electricity.

3. Metals have high tensile strength. .

4. Metals are sonorous.
5. Metals are hard.

Properties of non metal

1. High ionization energies.

2. High electronegativities.

3. Poor thermal conductors.

4. Poor electrical conductors.

5. Brittle solids—not malleable or ductile.

6. Little or no metallic luster.

7. Gain electrons easily.

Answer:

The avocado consists of around 73% water, 15% fat, 8.5% carbohydrates — mostly fibers — and 2% protein. Half an avocado, at around 100 grams (g) contains 160 calories ( 1 ).

Answer:

3.2×10^-3 mol

Explanation:

The equation for molarity is M= n/L. Where "M" is Molarity, "n" is the number of moles of solute, and "L" is the total liters in solution.

The question gives you the volume in mL, so to convert "mL" to "L" you need to divide by 1000. (6.70mL/ 1000L)= 0.0067L.

Now you can plug the numbers into the equation. 0.480M= n/ 0.0067L), multiply (0.480M×0.0067L)= 0.003216 mol. The scientific notation is 3.2×10^-3, 10^-3 because you move the decimal back three times and 3.2 because there are 2 sig figs.