When 2 moles of
H₂(g) react with
O2(g) to form
H₂O(g) according to the following
equation, 484 kJ of energy are
evolved.
2H2(g) + O2(g) → 2H₂O(g)
Is this reaction endothermic or
exothermic?
exothermic
What is the value of q? _____kj

Is this reaction endothermic or exothermic ?

Answer: a

Explanation:

The concentration of sodium ions in 0.130 M Na₂HPO₄  is 0.26 M.

The Na₂HPO₄ will dissociates in to ions we get :

Na₂HPO₄  ---->  2Na⁺   +  HPO₄⁻

here from the above equation it is clear that,the  1 moles of Na₂HPO₄ produce the 2 moles of Na⁺  and 1 mole of Na₂HPO₄  will produce 1 mole of  HPO₄⁻.

the concentration of Na⁺ = ?

concentration of the Na⁺ = 2 × Na₂HPO₄

concentration of the Na⁺ = 2 × 0.130 M

the concentration of the Na⁺ = 0.26 M    

Thus,  The concentration of sodium ions in 0.130 M Na₂HPO₄  is 0.26 M.

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n=3 <— n=5, n= 2 <— n=4 are most energy emitted and n=1 —> n=3, n=2 —> n=4 are most energy absorbed

In chemistry, energy is the capacity to carry out work. It may take on a variety of shapes, including potential, kinetic, thermal, electrical, chemical, radioactive, etc. Heat and labor are other examples of energy being transferred from one body to another. Once it has been transported, energy is always allotted according to its kind. Thus, heat transmission might manifest as thermal energy, but work could produce mechanical energy.

All energy kinds have the characteristic of motion. For instance, a body has kinetic energy if it is moving. A tensioned item, such as a spring or bow, has the capacity to move even while at rest; this property results from the design of the object, which incorporates potential energy.

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Answer: copper is a fcc.

Explanation:

Solid copper can be described as the arrangement of copper atoms in a face-centered-cubic (fcc) configuration.

Solid copper can be described as the arrangement of copper atoms in a face-centered-cubic (fcc) configuration.

Two of the most recognizable crystal shapes are face-centered cubics (FCC) and body-centered cubics (BCC). There are FCC, BCC, or HCP structures for almost all elements.

The atomic configurations are where FCC and BCC crystals diverge most drastically. All 8 corner positions and the centers of each of the six faces are occupied by atoms in the face-centered cubic structure. All eight corner positions and the cube's center are occupied by atoms in the body-centered cubic structure.

Compared to BCC metals, FCC metals are often more ductile, more stable at high temperatures, and more dense. This is a result of their packaging design and slip systems.

The most effective atomic configuration is found in FCC (tied with HCP).

Because of this, we refer to FCC as a "close-packed" structure. FCC metals will typically be more dense and stable because FCC atoms are grouped more tightly together than BCC atoms.

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The molar mass of the protein under the conditions that we have in this question can be obtained to be 12065 g/mol.

We know that the osmotic pressure is one the colligative properties of the solution. The colligative properties are the properties that depend on the amount of substance that is present in the solution.

Mass of the protein = 0.135 g

Volume of the solution = 2.00 mL

Temperature of the system = 28 ∘C + 273 = 301 K

Osmotic pressure of the solution = 0.138 atm

We can get the osmotic pressure from;

π = iCRT

π = Omotic pressure

i = Van't Hoff factor

C = concentration of the solution

R = gas constant

T = temperature

Let the molar mass of the protein be M

0.138 = 1 * 0.135/M/0.002 * 0.082 * 301

0.138 =  1 * 0.135/0.002M * 0.082 * 301

0.138 = 3.33/0.002M

0.138 * 0.002M  = 3.33

M = 3.33/0.138 * 0.002

M = 12065 g/mol

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Answer: shielding constant is +20.494 ppm for σ(P) and À0. 221 ppm for σ(H).

The new volume of the balloon will be 484.43 L.

This is an example of Charles' law, sometimes called the temperature-volume law. It states that the volume of a gas is directly proportional to the Kelvin temperature, while pressure and amount are held constant.

The equation is V1/T1=V2/T2, where V is volume and T is temperature in Kelvins.

Known

V1=556 L

T1=30∘C+273.15=303 K

T2=-9∘C+273.15=264 K

Unknown

V2

Solution

Rearrange the equation to isolate V2. Substitute the known values into the equation and solve.

V2=V1T2/T1

V2=(556L×264K)/303K=484.43 L.

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Answer:

Chemical bonding is the process by which atoms are held together to form molecules. The bond between atoms is created by the sharing of electrons. The electrons are attracted to the nucleus of the atoms, which creates a force that holds the atoms together.

Answer:

Below

Explanation:

125 ml = .125 L

.125 L  *   1.241  g/ L   = . 155 g

As per the balanced reaction, 2 moles of potassium gives 2 moles of hydrogen molecules. Thus 11.5 g or 0.302 mol will produce 0.302 moles of hydrogen. The mass of 0.302 mol of hydrogen is 0.604 g.

Hydrolysis is the reaction of a substance with water to form hydroxides or hydrides. The given reaction is hydrolysis of potassium giving 2 moles of H2.

The atomic mass of potassium is 38 g/mol. Thus the mass of 2 mole of potassium is 38 × 2 = 76 g. The number of moles in 11.5  g K is 0.302 moles. 2 moles of potassium gives 2 moles of H2, thus 0.302 moles gives 0.302 moles of H2.

The molecular mass of H2 is 2 g/mol. Thus mass of 0.302 moles is 0.302 × 2 = 0.604 g.

Hence, the mass in grams of hydrogen produced is 0.604 g.

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Answer: What are the answer choices?

Explanation: I need answer choices to see, there are a lot of definitions, verbs and nouns  for an answer.

Nuclear reactions involve a change in an atom's nucleus, usually producing a different element. Chemical reactions, on the other hand, involve only a rearrangement of electrons and do not involve changes in the nuclei. Different isotopes of an element normally behave similarly in chemical reactions.

I hope this helps!

Carbon dioxide is generated when any substance that contains carbon is burned. It is also a product of respiration and fermentation. Plants absorb carbon dioxide during photosynthesis.

Answer:

2.2

Explanation:

Answer: The mass of KOH needed is 28 grams

Explanation:

Molarity: It is defined as the number of moles of solute present in one liter of solution.

In this question, the solute is KOH.

The formula used: M = N/V

wb = mass of solute KOH = ?

mb = molar mass of solute KOH = 56 g/mole

V = volume of solution = 250 ml

Molarity = 2.00 M = 2.00 mole/L

Now put all the given values in the above formula, and we get the mass of KOH.

Now put all the given values in the above formula, and we get the mass of KOH.

Therefore, the mass of KOH needed is 28 grams.

Answer: 28 grams

Explanation:  

2molarity/L= Mass of KOH/ 56g/molarity multiplied by 250ml multiplied by 1000 *Hope it helped*

If actual yield and theoretical yield are same then the percent yield will be 100%. Generally, the actual yield is lower than the theoretical yield. The percent yield of  0₂ is 93%.

Percent yield is the percent ratio of actual yield to the theoretical yield.

Mathematically,

Percent yield= actual yield of a product÷ theoretical yield of the product

The balanced reaction is

2Al₂O₃ →4A1+30₂

moles of Al₂O₃=given mass÷ molar mass

                        =96.3 g ÷100g/mol

                        =0.96moles

From 2 mole of Al₂O₃, 3 moles of 0₂ is produced

From 0.96moles of  Al₂O₃=(3÷2)×0.96moles of 0₂

                                          =1.44moles of 0₂

mass of  0₂=moles of  0₂×Molar mass of moles of 0₂

mass of  0₂=1.44×32

                  =46.08g

Percent yield=  43.2 g÷46.08g=93%

Therefore the percent yield of  0₂  is 93%.

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Four possible sub levels an electron can occupy are s, p, d, f

A level that is lower than or subordinate to another level called as sublevel and electron fill principal energy level or shell to have lowest possible energy and within the shell they also fill the sublevel are s,p,d,f to have the lowest energy and so electron in orbital in the s sublevel called s orbital and have less energy than those in p sublevel and the s sublevel has just one orbital and so can contain 2 electron maximum and the p sublevel has 3 orbital and so can it contain 6 electron maximum and in d 5 orbital and it contain 10 electron and f has 7 orbital and it contain 14 electron maximum

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The amount, in grams, of calcium that are in 3.01 x [tex]10^{22[/tex] atoms of calcium would be 1.9992 grams.

According to the rules, 1 mole of any substance contains Avogadro's number, which is 6.022 x [tex]10^{23[/tex] atoms or molecules.

Now, we have a substance with  3.01 x [tex]10^{22[/tex] atoms of calcium.

If, 1 mole = 6.022 x [tex]10^{23[/tex] atoms

Then, 3.01 x [tex]10^{22[/tex] atoms = 3.01 x [tex]10^{22[/tex]/ 6.022 x [tex]10^{23[/tex]

                                       = 3.01/60.22

                                       = 0.04998 moles

Recall that:

Mole = mass/molar mass

The molar mass of the calcium atom is 40 g/mol.

Thus, the mass of 0.04998 mole of calcium = mole x molar mass

                                                                          = 0.04998 x 40

                                                                           = 1.9992 grams

In other words,  3.01 x [tex]10^{22[/tex] atoms of calcium would weigh 1.9992 grams of ca.

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Answer:

below

Explanation:

From periodic table:

Arsenic is a metalloid in the family with Silicon (Si) which has a mass of 14

a) The reaction between magnesium chloride solution and sodium carbonate solution is a displacement reaction

b) Aluminum is above copper but below magnesium in the electrochemical series.

We know that a displacement reaction is the kind of reaction that occurs between two substances which involves an exchange of radicals. Now we know that a reaction would certainly produce a new kind of chemical substances.

A displacement reaction would occur if the substances that are involved in  the reaction are far apart in the activity series. The metal that is more reaction would displace the metal that is less reactive from its salt.

Given the fact that sodium is higher than magnesium in the electrochemical series, then magnesium can be displaced from its solution by sodium

In part 2, the aluminum metal is ahead of copper in the electrochemical series hence aluminum is able to displaces  copper from its solution but it is unable to displace magnesium from its solution because magnesium is above aluminum in the electrochemical series.

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1. The reaction between magnesium chloride solution and sodium carbonate solution is a displacement reaction

2. Aluminum is above copper but below magnesium in the electrochemical series.

Answer:

2

Explanation:

Answer: Glass or plastic

Explanation:

Because they both are able to shatter hehehhe ;)))))))

Acacia ant and acacias animals are an example of coevolution

Coevolution is the reciprocal evolutionary change in a set of interacting population over time resulting from the interaction between those population and an example of coevolution that is not characteristics of an arm race but one which provides a mutual benefit to both a plant species and insect is that of the acacia ant and acacia plant and many cases of coevolution can be found between plants and insects

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The volume of water that should be added in the given solution is equal to 202 ml.

The concentration or the volume of the dilute or concentrated solution can be calculated from the following equation:

M₁V₁ = M₂V₂

where M₁, V₁, M₂, and V₂ are the concentration and volume of the concentrated solution and dilute solution respectively.

Given, the concentration of the solution, M₁ = 0.14 M

The concentration of the diluted solution, M₂ = 0.100 M

The volume of concentrated solution, V₁ = 505 ml

Put the value of the molarity and volume in equation (1):

(0.140)× (505) = (0.100) × (V₂)

V₂ = 707 ml

The amount of water should be added = 707 - 505 = 202 ml

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According to the law of conservation of mass, the total mass of the reacting substances is

A. always more than the total mass of the products.

B. always less than the total mass of the products.

C. sometimes more and sometimes less than the total mass of the products.

D. always equal to the total mass of the products.​

This is the one that I would have to choose.

Hope this helps:)

Answer:

CuCl2 + Aluminum = Chemical / Physical change