The thermite reaction ,
Fe2O3(s)+2Al(s)⟶2Fe(s)+Al2O3(s),ΔH∘=−851.5kJ/mol
is one of the most exothermic reactions known. Because the heat released is sufficient to melt the iron product, the reaction is used to weld metal under the ocean. How much heat is released per mole of Al2O3produced? How does this amount of thermal energy compare with the energy released when 2 mol of protons and 2 mol of neutrons combine to form 1 mol of alpha particles?

melting of wax is a physical reaction, because the same amount of wax exists before and after the change.

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Answer:

burning paper

Explanation:

i think its burning paper.

Answer:

That`s tough for me to answer, but the definition is to retain, or require heat or energy to make a function of process. I would think it is fireworks, because a chemical reaction is required to produce the effects, but each answer retains heat in some way. I would still choose fireworks though. Hope that helps . . .

Answer:

they are known as halogens

Explanation:

everything else is correct

Answer:

[no2]- it have 1 negative charge

O-N=O

this Single bond O having negative charge because oxygen need 2 electrons to complete its octet and it have only one bond to complete its octet it having one more electron and this one one more electron creates 1 negative charge on this compound

Answer:

Make high energy molecules for the cell to function.

Explanation:

Remember mitochondria is the storehouse of the cell.

Hope it helps!

Answer:

You can not make the observation in the lab

Explanation:

We must know the amount of Nitrogen-16 that remains after 57 seconds before we can make our conclusion.

Hence, from;

N/No = (1/2)^t/t1/2

Where;

N = amount of Nitrogen-16 present after 57 seconds

No = 100g of Nitrogen-16 originally present

t = 57 seconds

t1/2 = half life of Nitrogen-16 which is 7.13 seconds

Substituting values;

N/100 = (1/2)57/7.13

N/ 100 =(1/2)^8

N/100 = 1/256

256N = 100

N = 100/256

N = 0.39 g

You can not make the observation because you need at least 5g of Nitrogen-16 and only 0.39 g is left after 57 seconds.

The minimum amount of sample required has been 5 grams, while the remaining sample has been 0.39 grams. Thus, it has not been possible to make the observations.

The half life can be defined as the time required for the sample to reduce to half of its initial concentration. The half life can be given as:

Amount remained = Initial amount [tex]\rm \times\;\dfrac{1}{2}^\dfrac{time}{Half-life}[/tex]

The half life of nitrogen 16 has been 7.13 second.

The initial concentration of the sample has been 100 grams.

The concentration of sample remained after 57 seconds has been:

Amount remained = 100 [tex]\rm \times\;\dfrac{1}{2}^\dfrac{57\;sec}{7.13\;sec}[/tex]

Amount remained = 0.39 grams.

The amount of sample remained after 57 seconds has been 0.39 grams.

The amount of sample required for the analysis has been 5 grams, after 57 seconds only 0.39 grams of sample has been remaining. Thus, the student will not be able to made analysis of nitrogen-16.

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Answer:

CuSO4 + 2NH4OH -----> Cu(OH)2 + (NH4)2SO4

Explanation:

Answer:

ndcuffaStuff that restrains you from something or someone basicially handcuffs or shackles

Explanation:

Answer:

a limitation or restriction.

OR

stiffness of manner and inhibition in relations between people.

Answer:

4 elements carbon hydrogen nitrogen and oxygen are present in alanine.

Explanation:

Its formula is C3H7NO2 which show all above 4 elements

Answer: The concentration of Pb2+ in the anode compartment is [tex]1.74\times 10^{-6}M[/tex]

Explanation:

[tex]Sn^{2+}(aq)+Pb(s)\rightarrow Sn(s)+Pb^{2+}(aq)[/tex]

Here Pb undergoes oxidation by loss of electrons, thus act as anode. Sn undergoes reduction by gain of electrons and thus act as cathode.

[tex]E^0=E^0_{cathode}- E^0_{anode}[/tex]

Where both [tex]E^0[/tex] are standard reduction potentials.

[tex]E^0_{[Sn^{2+}/Sn]}=-0.14V[/tex]

[tex]E^0_{[Pb^{2+}/Pb]}=-0.13V[/tex]

[tex]E^0=E^0_{[Sn^{2+}/Sn]}- E^0_{[Pb^{2+}/Pb]}[/tex]

[tex]E^0=(-0.14-(-0.13)V=-0.01V[/tex]

Now using Nernst Eqn :

[tex]E=E^0-\frac{0.059}{n}\log\frac{[Pb^{2+}]}{[Sn^{2+}]}[/tex]

[tex]0.16=(-0.01)-\frac{0.059}{2}\log\frac{[Pb^{2+}]}{[1.00]}[/tex]

[tex]0.17=-0.0295\log\frac{[Pb^{2+}]}{[1.00]}[/tex]

[tex]-5.76=\log\frac{[Pb^{2+}]}{[1.00]}[/tex]

[tex]1.74\times 10^{-6}=\frac{[Pb^{2+}]}{[1.00]}[/tex]

[tex][Pb^{2+}]=1.74\times 10^{-6}[/tex]

Answer:

0.93 mol

Explanation:

Given data:

Number of moles of Na atom = ?

Number of atoms = 5.60× 10²³

Solution:

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

5.60× 10²³ atoms ×  1 mol / 6.022 × 10²³ atoms

0.93 mol

Answer:

The four spheres of it are,

Explanation:

1. Lithosphere

2. Atmosphere

3. Biosphere

4. Hydromasphere

May It's Help U

Answer:

0.285 L

Explanation:

285ml divided by 1000=0.285L

Answer:

The pressure should be 21 atm. You can change units if needed

Explanation:

use the forumla PV=nRT. To figure out pressure you need to divide by the volume on each side. the put the apporite units into the formula and Bam. u got it

Answer: They always have the same functional groups.

Explanation:

use quizlet too if you have toooo

Answer:

they have same physical properties is not true

Writing each number in full form, we have;

We know that scientific notation affords us the opportunity to write numbers in a  manner that is shorter and saves space by the use of exponents.

We shall now try to write each number in the full form;

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Answer:

Fe2O3 - S

PbO2 - D

PbO - I

Fe2O - U

Fe(OH)3 - H

FeO2 - T

FeO - R

Pb2O - G

Pb(OH)2 - O

FeOH - N

Pb(OH)3 - A

Explanation:

In writing the formula of ionic compounds we consider the valency or oxidation state of each ion.

For instance, given the compound iron II oxide. The oxidation states of both iron and oxygen are +2 and -2 respectively. Ignoring the charges, this cancels out and we have FeO as the correct formula of the compound.

For Iron III oxide, the oxidation states of iron and oxygen are +3 and -2 respectively, the both atoms exchange charges. If we ignore the signs and write the exchanged numbers as subscripts we obtain the formula Fe2O3.

Answer:

b its radiant energy that heats up the earth.

Explanation:

Answer:

The answer is D

Explanation:

Heat from the Earth's core and radiation from the Sun is transferred to the surface of the Earth by conduction. The warm land and water radiates infrared, some of which is absorbed by the atmosphere, adding to its thermal energy.

Answer:

c, maybe d, and I think b.

Explanation:

Im sorry if wrong

largest freshwater body on Earth by volume, at 5666 mi³

1 mi³= 4.168  ×  10^12 L

5666 mi³ = 5666 × 4.168 × 10^12 L

  volume   = 2.362 × 10^16 L

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Answer:Ca C2h3o2 2

Explanation

find the molar mass of the compound

ca : 1 X 40.1 = 40.1

c: 4 x 12.01 = 48.04

H: 6 X 1.01 = 6.06

O: 4 X 16 = 64

add these up and get 158.11

then divide 158.11 by each element massand multiply by 100

Ca: 40.01/158.11 X 100 = 25.3%

C: 30.4%

H:3.8%

O: 40.5%

Answer:

B. Color change

3&5

hope this helps <3

have a great day/night

-Dan

This is a single displacement reaction. In this reaction, Iron reacts with aqueous solution of copper chloride, which is blue in colour.

The Iron being more reactive, reduces the copper from its solution to make Iron Chloride, which is green in colour. Fe + CuCl₂ → FeCl₂ + Cu. This is also a redox reaction in which CuCl₂ is a reducing agent and Fe is an oxidising agent. 

Thus, the reaction between Iron and Copper sulphate is a redox displacement reaction.

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Disclaimer: The question was incomplete. The correct question can be:

In the reaction between Fe and CuCl₂, the following statement is true:

A) It is a single displacement reaction.

B) It is a combination reaction.

C) It is a decomposition reaction.

D) It is a double displacement reaction.

what will happen of sodium and water react(be careful)

make slime

make chapathi and paneer butter masala

Answer:

True

Explanation:

Answer:

Nitrogen group element, any of the chemical elements that constitute Group 15 (Va) of the periodic table. The group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and moscovium (Mc)

Explanation: Hope i helped! :D

Answer:

Empirical formula = Fe₃O₄

Explanation:

Given data:

Percentage of Fe = 72.36%

Percentage of oxygen = 27.64%

Empirical formula = ?

Solution:

Number of gram atoms of O = 27.64 / 16 = 1.7

Number of gram atoms of Fe = 72.36 / 55.8 = 1.3

Atomic ratio:

                          Fe                    :         O

                           1.3/1.3              :     1.7/1.3

                              1                    :       1.3            

Fe : O = 1 : 1.3

Empirical formula = 3( 1: 1.3)

Empirical formula = Fe₃O₄