The only sure evidence for a chemical reaction is

Answers

Answer 1

Answer:

that one or more new substances are produced. Temperature Changes Chemical reactions can release energy or absorb energy.

Explanation:       .


Related Questions

Humans have 50 pairs of chromosomes true or false

Answers

Answer:

False

Explanation:

humans have 23 pairs

Electron transfer between redox centers in proteins is controlled by quantum tunneling. We can model the region between two redox centers as an energy barrier which the electron must cross. If the distance between the redox centers is 0.681 nm and the energy of the electron is 0.5540.554eV lower than the height of the barrier, what is the probability that the electron will successfully cross to the next redox center

Answers

Answer:

5.61 e⁻³

Explanation:

Given that:

The barrier length = 0.681 nm = 6.81 × 10⁻¹⁰

The difference between the height of the barrier & the energy of the electron is;

[tex]V - E = 0.554 \ eV (1.6 \times 10^{-19} )[/tex]

= 8.864 × 10⁻²⁰ V

where;

m = 9.1 × 10⁻³¹ kg

The probability[tex]P = e^{-2 \ kd}[/tex]

[tex]k = 2 \pi \sqrt{\dfrac{2m (V-E)}{h^2} }[/tex]

[tex]k = 2 \pi \times \dfrac{\sqrt{2 \times 9.1 \times 10^{-31} \times 8.864 \times 10^{-20}}}{6.63 \times 10^{-34}}[/tex]

k = 3.806 × 10⁹

[tex]P = e^{-2 \ kd}[/tex]

[tex]P = e^{2 \times 3.806 \times 10^9 \times 6.81 \times 10^{-10}}[/tex]

P = 0.005606

P = 5.61 × 10⁻³

P = 5.61 e⁻³

What is the molarity of a NaOH solution if 28.2 mL of a 0.355 M H2SO4 solution is required to neutralize a 25.0-mL sample of the NaOH solution?A) 0.801B) 0.315C) 0.629D) 125E) 0.400

Answers

Answer:

A) 0.801

Explanation:

The reaction that takes place is:

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

First we calculate the H₂SO₄ moles that reacted:

0.355 M * 28.2 mL = 10.011 mmol H₂SO₄

Now we convert H₂SO₄ moles to NaOH moles:

10.011 mmol H₂SO₄ * [tex]\frac{2mmolNaOH}{1mmolH_2SO_4}[/tex] = 20.022 mmol NaOH

Finally we calculate the molarity of the NaOH solution:

20.022 mmol NaOH / 25.0 mL = 0.801 M

So the answer is option A.

The molarity of the NaOH solution used in the neutralization reaction has been 0.801 [tex]\rm \times\;10^-^3[/tex] M. Thus, option A is correct.

The neutralization reaction has resulted in the formation of the salt and water on reacting an acid with a base. In the neutralization reaction, the strength of acid and base can be given as:

[tex]\rm 2\;NaOH\;+\;H_2SO_4\;\rightarrow\;Na_2SO_4\;+\;H_2O[/tex]

For the neutralization of 1 mole of sulfuric acid, 2 moles of NaOH has been required.

The moles of sulfuric acid can be given as:

Moles = Molarity × Volume

Given, the molarity of acid ([tex]\rm H_2SO_4[/tex]) = 0.355 M

Volume of acid = 28.2 ml = 0.0282 L

Volume of base (NaOH) = 25 ml = 0.025 L

Moles of [tex]\rm H_2SO_4[/tex] = 0.355 × 0.0282 mol

Moles of [tex]\rm H_2SO_4[/tex] = 10.011  mol.

Since, 1 mole [tex]\rm H_2SO_4[/tex] = 2 moles NaOH

10.011 moles [tex]\rm H_2SO_4[/tex] = 10.011 × 2 moles NaOH

10.011 moles [tex]\rm H_2SO_4[/tex] = 20.022 moles NaOH.

The neutralization of 0.355 M [tex]\rm H_2SO_4[/tex] requires 20.022 moles NaOH. The strength of the NaOH solution will be:

Molarity = [tex]\rm \dfrac{Moles}{Volume\;(L)}[/tex]

Molarity of NaOH = [tex]\rm \dfrac{20.022}{0.025}[/tex]

Molarity of NaOH = 0.801 [tex]\rm \times\;10^-^3[/tex] M.

The molarity of the NaOH solution used in the neutralization reaction has been 0.801 [tex]\rm \times\;10^-^3[/tex] M. Thus, option A is correct.

For more information about the neutralization reaction, refer to the link:

https://brainly.com/question/4612545

What is electron affinity? ​

Answers

Answer:

The ability of an atom to accept an electron.

Explanation:

Electron affinity is measured by observing the energy change of a substance when an electron is added to it in its neutral gas form. For example, elements that are on the far right of the periodic table (excluding noble gases) are more likely to accept electrons rather than give them up. This is why Fluorine has the highest electron affinity of all atoms on the periodic table.

What's the electron configuration of an N-3 ion?
Question 17 options:

A)

[Ne]

B)

[Ar]

C)

[H]

D)

[He]

Answers

Answer:

A. since Nitrogen has 7 electrons and when it gains 3 electrons it will have 10 electrons. using short hand rule it is [Ne]

WILL BE MARKED BRAINLIEST IF U ANSWER CORRECT


PLUS 30 PT

Why does DNA dissolve in water?



Why is salt added to solution of DNA and water?



How does ethanol help the precipitate form?



After a pellet is formed, is the DNA in the pellet or the supernate?

Answers

Explanation:

Because of this, DNA and RNA can easily dissolve in water. ... Adding ethanol helps the Na+ and PO3- ions come together, because ions travel easier in ethanol than water. The supernate is removed and new ethanol is added in the second washing. This removes any residual salt that remained on the pelleted DNA.

Answer:

DNA is polar due to its highly charged phosphate backbone. Its polarity makes it water-soluble (water is polar) according to the principle "like dissolves like". ... This fact makes water a very good solvent for charged compounds like salts.

Your DNA's sugar phosphate backbone is charged. By adding salt, we help neutralize the DNA charge and make the molecule less hydrophilic, meaning it becomes less soluble in water. The salt also helps to remove proteins that are bound to the DNA and to keep the proteins dissolved in the water.

It is well known that Ethanol has a lower dielectric constant than water, making it to promote ionic bond formations between the Na+ (from the salt) and the PO3- (from the DNA backbone), further, causing the DNA to precipitate.

Explanation:

Ideally DNA needs to be precipitated with pellet and should not remain in supernatant. DNA is acidic in nature and therefore, needs optimum salt concentration in the buffer to be pelleted from a solution. At very low salt concentration or without salt DNA would remain in supernatant.

This item is used for small cuts and peeling.
1-Chef Knife
2-Pizza Cutter
3-Kitchen Shears/Scissors
4-Paring Knife

Answers

I would say #3 I’m sorry if it’s wrong tho

A compound is an example of pure substance

True

False

Answers

The answers to that is true!!!

Which is stronger, the strong force (SF) or the electromagnetic force (EMF)? Describe how they battle each other in the nucleus. What would happen if their strengths were reversed?

Answers

Answer:uclear Force that holds together the nucleus of an atom. electromagnetic force. ... They are unstable because the Strong Force that would hold them together if the protons and neutrons were closer is weakened because the protons and neutrons get too far apart.

Explanation:

How high of a Frequency would a photon have to be for it to have an energy of 4 joules

Answers

The frequency of photon=6.03 x 10³³ /s

Further explanation

Radiation energy is absorbed by photons

The energy in one photon can be formulated as

[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]

Where

h = Planck's constant (6,626.10⁻³⁴ Js)

f = Frequency of electromagnetic waves

Energy of photon = 4 J

So the frequency :

[tex]\tt f=\dfrac{E}{h}\\\\f=\dfrac{4}{6.626.10^{-34}}\\\\f=6.03.10^{33}/s[/tex]

What are capacitors used for

Answers

its a basic storage device used to store electrical charges and release it as it is required by the circuit. they are also used as smoothing, filtering and bypassing

What do you have to do to break a molecule?

Answers

Answer:

Heat the molecule

Explanation:

Since most bonds require energy to form, they also give off energy when they are broken. But before most bonds break, the molecule has to be heated. Then the atoms start to move, and when they move too much, the bond breaks. Molecules that require less energy to break than they give off when broken are called fuels.

Decide which element probably has a boiling point most and least similar to the boiling point of aluminum.
Comparing boiling point:
gallium rubidium magnesium oxygen
most similar to aluminum
least similar to aluminum

Answers

Answer:

The boiling point of gallium would be most similar to aluminum, and the boiling point of oxygen would be least similar to aluminum.

Explanation:

The atomic number of aluminum is 13, in the periodic table, magnesium lies in a similar period as Aluminum and Gallium is also present in a similar group. Thus, it can be expected that both magnesium and gallium exhibits similar boiling points with aluminum. However, gallium is a poor non-metal just like aluminum, while magnesium is a metal. Thus, it can be said that the boiling point of aluminum is more similar to gallium.

Now of the given elements, oxygen is a gas, thus, the boiling point of oxygen would be least similar to aluminum.

what is protein denaturation​

Answers

Answer:

Denaturation is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some

Explanation:

Why is a “spark” of energy required to begin the chemical reaction of burning a fossil fuel? What is another name for this spark of energy?

Answers

Answer: a burst

Explanation: a burst of energy could be substatuded for spark of energy

A spark of energy is required to begin the chemical reaction of burning a fossil fuel because; This spark of energy is required to attain the activation energy of the reaction.

Another name for this spark of energy is Ignition.

Definition:

The activation energy of a chemical reaction is the minimum amount of energy required for the commencement of the chemical reaction.

In this case, the spark of energy is required to attain the activation energy of the reaction.

Read more:

https://brainly.com/question/7639475

4. Look at the equation below and determine what fitsI in the empty box.
14 C --> 4 N+
?
re
c. en TH
What belongs in the empty box?
A.
В.
e
D.

Answers

Answer:

Beta particles

Explanation:

A beta emission is said to occur when a neutron is converted into a proton. When a beta emission takes place, the daughter nucleus increases it's atomic number by 1. A neutrino is also produced.

Since the mass number remain the same but the daughter nucleus has it's atomic number increased by 1, then the particle is a beta particle.

The reaction between calcium carbonate (CaCO3) and HCl produces calcium chloride (CaCl2), carbon dioxide (CO2), and water (H2O).What happens when the concentration of hydrogen chloride (HCl) molecules is doubled in this reaction?

CaCO3 + 2HCl → CaCl2 + CO2 + H2O

Answers

Answer:

yes that is right

Explanation:

Answer: what is the answer im on plato

Explanation:

What is a solute?
A material that is dissolved in another material.
O A material in which another material is dissolved.
An area of space surrounding the nucleus.
O Chemical formulas on the left side of an equation.

Answers

A material that is dissolved in another material.

which of the following is an isotope of hydrogen​

Answers

Z=1 is the formula i would have to see the following lol

What is the degree of oxidation of a simple substance​

Answers

The oxidation state of a free element (uncombined element) is zero. For a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion. For example, Cl– has an oxidation state of -1. When present in most compounds, hydrogen has an oxidation state of +1 and oxygen an oxidation state of −2.

Answer:

The oxidation state of a free element (uncombined element) is zero. For a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion. For example, Cl– has an oxidation state of -1. When present in most compounds, hydrogen has an oxidation state of +1 and oxygen an oxidation state of -2

Explain how atoms organize to create larger structures?

Answers

Answer:

First of all they are super tiny particles of neutrons, electrons and protons. Then they come together to organize a structure of atom. Atoms come together to form a molecule and smaller molecules work together to form macromolecules. Thus, how they organize and form building blocks of a substance.

Hope it helps!<3

Pro
∆G0=-RT in k Known as​

Answers

Answer:

Gibbs free energy equation

Explanation:

At what temperature is water a gas

Answers

Answer:

212 degrees Fahrenheit

Explanation:

When liquid water reaches a low enough temperature, it freezes and becomes a solid—ice. When solid water is exposed to enough heat, it will melt and return to a liquid. As that liquid water is further heated, it evaporates and becomes a gas—water vapor.

15 points! Answer only if you can please!
1. Have you ever grabbed the handle of a hot metal pan? Why did it feel hot to you?

2. What would happen if a person who is wearing a heavy winter jacket were to place a thermometer inside the jacket next to his or her skin? What would happen if we took the same jacket, after it had been hanging in a closet, and placed a thermometer inside?

3. How do you think the transfer of thermal energy causes unpopped popcorn kernels to pop?

Answers

Answer:

1. Yes

2. it would be the same i guess

3. because it travels to popcorn kernels with its heat and makes it pop'

did i get it right?

Explanation:

Percent yield is very important in terms of money. The higher the percent yield, the more of a product you can make. If you are working for a drug company and your theoretical yield is 120 kg, but you actually made 105 kg, what is your percent yield?
A. 8.75%
B. 114%
C. 87.50%
D. 15.00%

Answers

Answer:

87.5 %

Explanation:

Step 1: Given data

Theoretical yield: 120 kgReal yield: 105 kg

Step 2: Calculate the percent yield

When working with chemical reactions, we can determine the efficience in obtaining a product measuring the percent yield. The theoretical yield is the maximum amount of product that we could obtain according to the stoichiometry, whereas the real yield is the amount of product that we actually obtain when we carry out the process. We can calculate the percent yield usign the following expression.

%yield = real yield / theoretical yield × 100%

%yield = 105 kg / 120 kg × 100%

%yield = 87.5 %

Help me please this is due today

Answers

The only thing I can remember from chem that pertains to this is that a neutral solution will have a pH of 7.
Also, I’m pretty sure acidity & pH have to do something with hydrogens ions or something. Sorry, hope this helps at least a little.
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