Which event is an example of an exothermic reaction?(1 point)
A. Combustion
B. Evaporation
C. Decomposition
D.Melting ice

Answers

Answer 1

Answer:

Combustion

Explanation:

An exothermic reaction is defined as a reaction that releases heat and has a net negative standard enthalpy change. Examples include any combustion process, rusting of iron, and freezing of water.

Answer 2

Combustion is a type of exothermic chemical reaction that generates light and heat in most cases, and occurs fairly quickly.

What is an exothermic reaction?

An exothermic reaction is one that when it occurs releases energy in the form of heat or light to the environment.

Characteristics of an exothermic reaction

When this type of reaction occurs, the products obtained have lower energy than the initial reactants.

Most of the exothermic reactions are oxidation, and when they are very violent they can generate fire, as in combustion.

Combustion is a very fast oxidation reaction that occurs between materials called fuels and oxygen.

Therefore, we can conclude that combustion is an example of an exothermic reaction that releases large amounts of heat, which can lead to fire.

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Related Questions

How many oxygen do we have in the FE2(so4)3

Answers

Explanation:

What do you mean by 'how many oxygen'?

oxygen atoms? or oxygen percentage?

if oxygen atoms is 12 atoms

name the main form of energy released by the reaction between hydrogen and oxygen inside a combustion engine

Answers

Answer:

When molecular hydrogen (H2) and oxygen (O2) are combined and allowed to react together, energy is released and the molecules of hydrogen and oxygen can combine to form either water or hydrogen peroxide . These two processes are represented by the two chemical equations shown at right.

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the mechanism of phosphorus fixation in the alkaline soil and acid soils​

Answers

Answer:

absorption or precipitation or by both

Explanation:

Convert 12.044×10²² molecules of sulphur dioxide into moles​

Answers

Answer:

➜ Properties of liquids and gases. Liquids have a fixed volume but no fixed shape. Gases have no fixed volume and no fixed shape. Gases expand to fill the space available. They can also be compressed into a very small space.

Explanation:

12.044 × 10 ²³molecules of sulphur dioxide are 0.2 mole.

4.
TRUE OR FALSE?
Frequency is how often a wave occurs in a given time period.
Group of answer choices

True
False

Answers

Answer:

The answer to this question is True

Which element on the periodic table is the lowest mass in period 4??

Answers

Answer:

potassium I believe is the correct answer

Explanation:

Potassium is the period four element with the lowest mass; its average mass is 39.0983amu.

The fourth period of the periodic table is where potassium has its lowest atomic mass.

What is atomic mass?

Atomic mass is defined as the combined mass of an atom's protons, neutrons, and electrons.  The term "atomic mass" refers to the weight of an atom or molecule. To determine the average mass of elements and molecules as well as to resolve stoichiometry issues, the atomic mass is used.

An electrically neutral atom has an equal number of protons and electrons. As a result, using any of the two formulas, we may calculate the atomic mass of an element. The atomic mass of an element grows as we move from left to right in a period of the periodic table. In the fourth period of the current periodic table, Krypton has the highest atomic mass and potassium has the lowest.

Thus, the fourth period of the periodic table is where potassium has its lowest atomic mass.

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What is the correct form of the equilibrium constant for the reaction of hydrogen and oxygen to form water? The equation is:

2H 2( g) + O 2( g) ⇌ H 2O( g)

Kc = ([H2O]/[O2] [H2])

Kc = ([H2O]/[O2] [H2]2)

Kc = ([H2O]/[O2] [H22])

Kc = ([H2O]2/[O2] [H22])

Kc = ([H2O]/[O2] [2H2])

Answers

answer :

the second one.

how many molecules are in 18 grams of water

Answers

Answer:

6.023×10^23

Explanation:

Molecular mass= 2 (H)+1 (O) =2*1+1*16=2+16= 18 gm per 1gm molecule of water

determine the gram-formula mass of stearin acid C17H35COOH

Answers

Answer:

284.48 g/mol

Explanation:

You can find the molar mass of any molecule by looking at a periodic table and adding up all of the masses of each element. When you do this with stearic acid, you get somewhere around 284.5 g/mol. Hope this helped!

Pls answer this question

Answers

Answer:

A carbon dioxide and oxygen

Tums is a popular remedy for acid indigestion. A typical Tums tablet contains calcium carbonate mixed with inert substances. When ingested, it reacts with stomach acids (hydrochloric acid) to produce carbon dioxide gas. When a 1.241 g tablet reacted with 43.435 mL of hydrochloric acid, carbon dioxide gas was produced and the final solution weighed 52.122 g. Calculate the number of liters of carbon dioxide gas released. When a 1.241g Tums tablet reacted with 43.435 mL of hydrochloric acid (density: 1.140 g/mL), carbon dioxide gas was produced and the resulting solution weighed 50.571 g. Calculate the mass of carbon dioxide gas released.

Answers

The mass of CO2 obtained in the reaction by stoichiometry is 30.8 g.

The equation of the reaction is;

2HCl(aq) + CaCO3(s) -----> CaCl2(aq) + H2O(l) + CO2(g)

The mass of the HCl reacted is obtained from;

Density = mass/volume

Mass = Density × volume =  1.140 g/mL ×  43.435 mL = 49.5 g

Number of moles of HCl =  49.5 g/36.5 g/mol = 1.4 moles

If 2 moles of HCl reacts produces 1 mole of CO2

1.4 moles of HCl produces x moles of CO2

x = 1.4 moles × 1 mole/ 2 moles = 0.7 moles

Mass of CO2 produced = 0.7 moles  x 44 g/mol = 30.8 g

In the second case, the same volume of acid is used hence the same mass of CO2 is obtained.

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What was the name of the original supercontinent that wegener proprosed in his theory

Answers

Answer:

pangea

Explanation:

can some vitamins be considered water-soluble and others fat soluble?​

Answers

Answer:

Vitamins are classified as either fat soluble (vitamins A, D, E and K) or water soluble (vitamins B and C). This difference between the two groups is very important. It determines how each vitamin acts within the body.

What is a proofreading tip you should use to double check that your work is error free

Answers

How you can check to make sure your work is error-free is by:

Placing a ruler under each line as you are reading itIf you are able to, try checking your work when you are the most alert so it can be easier to track a mistakeTry to read it out loud if you are comfortable with thatYou can have a friend, family member, or teacher help read it and check over itThink about the common mistakes you makeIf your work is computer written then you can use a spell checker app such as GrammarlyRead over your work at least two or three times

Hope this Helps

1. How many atoms are in 1.00 mole of H?

Answers

Answer:

6.022 × 1023

Explanation:

1 mole of H:

The definition of Avogadro's number of 6.022 × 1023/mole is the number of atoms or molecules per one gram atomic weight. For one gram atomic weight of hydrogen with an atomic weight of one gram, one mole of hydrogen contains 6.022 × 1023 hydrogen atoms. 1.45⋅6.02⋅1023≈8.73⋅1023 hydrogen atoms.

1 mole:

The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. 12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms • The number of particles in 1 mole is called Avogadro's Number (6.0221421 x 1023).

in an H:

H: 2×2×4=16 atoms of hydrogen. C: It only appears once and without a subscript, so 1×4=4 .  O : Like carbon, it's 1×4=4 .

1.00 mole:

One mole is equal to 6.02214179×1023 atoms, or other elementary units such as molecules.

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PLEASE HELP ME!!

The molar mass of BF3 is 67.81 g/mol. How many molecules of BF3 are there in 2 g? (1 point)
A) 1.776 x 1022
B) 8.881 x 1021
C) 1.204 x 1024
D) 4.084 x 1025

Answers

Answer:

A

Explanation:

We are given that the molar mass of boron triflouride BF₃ is 67.81 g/mol. We want to determine the number of molecules of BF₃ in 2 g of BF₃.

Recall that there are 6.02 × 10²³ molecules in any mole of a substance. In other words, there are 6.02 × 10²³ BF₃ molecules in a mole of BF₃. Starting with the initial value, multiply:

[tex]\displaystyle \begin{aligned} 2\text{ g BF$_3$}&\cdot \frac{1\text{ mol BF$_3$}}{67.81 \text{ g BF$_3$}} \cdot \frac{6.02\times 10^{23} \text{ molecules BF$_3$}}{1 \text{ mol BF$_3$}} \\ \\ &= 1.776 \times 10^{22} \text{ molecules BF$_3$}\end{aligned}[/tex]

Hence, our answer is A.

*Perhaps it rendered the values incorrectly, but since we started with only 2 g of BF₃, our resulting calculation should only contain one significant digit. Hence, the correct answer should be 2 × 10²² molecules of BF₃.

The molecules of  BF₃ that are there in 2 g is 1.776 × 10²² molecules and the correct option is option A.

The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.

A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.

Given,

Molar mass of BF₃ = 67.81 g/mol

Mass = 2g

Moles = mass / molar mass

= 2 / 67.81

= 0.029 moles

1 mole = 6.023 × 10²³

0.029 moles = 6.023 × 10²³ × 0.029

= 1.776 × 10²² molecules

Thus, the ideal selection is option A.

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2. In which state of matter do particles vibrate in place? *
1 point
A. gas
B. solid
C. liquid

Answers

solid.................

Answer:

b solid

Explanation:

i know for a fact

The density of crystalline cl2 at 160K is 2.02g/cm3. calculate the molar volumes

Answers

molar volumes of the density of crystalline is 60

The molar volume (Vm) is the volume occupied by one mole of a chemical element or chemical compound at standard temperature and pressure (STP). The molar volume of Cl₂ is 35.10 cm³/mol.

One mole of any gas has a defined volume when it is at a particular temperature and pressure. The relationship between molar mass and molar volume is direct and inverse, respectively.

Two gases have equal molecules if their volumes are the same at a given temperature and pressure. A gas's volume is directly proportional to the number of moles it contains. One mole of any gas takes up 22.4 L of space at STP.

The expression used to calculate molar volume is:

Molar volume = Molar mass / Density

The molar mass of Cl₂ = 70.906 g/mol

Molar volume = 70.906 / 2.02

Molar volume = 35.10 cm³/mol

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Please help due tomorrow

Answers

Answer:

The gravitational force at the center of the Earth is 0.

The discrepancy between results given by the van der Waals equation and the ideal gas law will increase as:

Answers

This question is recalling the behavior of real gases in contrast to ideal gases, defined by the van der Waals equation and the ideal gas law respectively, and a reason behind the increasing discrepancy is required.

In such a way, we can start by considering the attached picture in which the choices are shown and clearly, the answer is "as the polarity of the molecules increase".

The aforementioned can be explained with the concept of intermolecular forces, because ideal gas theory states that ideal gas molecules do not interact one to another, and, as the polarity of the molecules increase, these intermolecular forces increase their frequency and strength, and will lead to the formation of associations, which fail to be numerically modelled by simple equations of state such as van der Waals, Redlich-Kwong, Peng-Robinson, etc,.

These associations are, of course, thoroughly neglected by the ideal gas law whereas the ones included in the van der Waals equation, which are not the most reliable, merely attempt to approach this phenomenon, which cause the mentioned discrepancy. As an additional data, robust equations of state, such as CPA (cubic plus association) are able to provide reliable results when working with highly polar gases but turn out really tough to work with due to its mathematical complexity.

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I don’t have baking powder or all of the 10 subs I found online. I wanna make pancakes any suggestions

Answers

Answer:

flour is the main ingredient sooo you need flour,sugar,salt milk,eggs,vegetable oil,vanilla optional.you can add baking powder or baking soda optional.

What element makes up graphene

Answers

Carbon makes up graphene NOT carbon dioxide

Read the statement. Magnesium atoms have 12 electrons, with the configuration 2-8-2. If the first five ionization energies of magnesium are shown, which ionization energy would show a sudden sharp increase?

Answers

The electronic configuration of magnesium is:

1s² 2s² 2p⁶ 3s² = [Ne] 3s²

This means that for a magnesium atom, in order to have its outermost orbital full, the easiest way would be to lose the two outermost electrons. This is seen in its relatively low first two ionization energies. The third ionization energy is several times higher because the ion would move from a stable form to an highly unstable form. (Mg⁺² → Mg⁺³ + e⁻).

Sodium only has one electron in its outermost orbital, so its first ionization energy would be several times lower than the second.

Which charge does iron (Fe) have in iron sulfate (FeSO4)?
A) -1
B) +2
C) -2
D)+2

Answers

I’m not sure but I think the answer is B

The charge on iron (Fe) in iron sulfate (FeSO₄) is equal to +2. Therefore, option (D) is correct.

What are the ionic charges?

The ionic charge can be described as the oxidation number of the chemical species. The cation carries a positive ionic charge while Anion carries a negative ionic charge. The number of electrons gained or lost by an atom decides the charge carried by ions.

In the modern periodic table, the elements placed on the left side are electropositive and act as metals because they can donate one or more electrons. The elements placed on the right side are electronegative as they can accept one or more electrons and get a negative charge on their ions.

Considering that the charge on the iron is x, We know that charge on the sulfate ion is -2.

x - 2 = 0

x = +2

Therefore, the charge on iron (Fe) in iron sulfate (FeSO₄) is +2.

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What is the lowest frequency photon that can ionize a hydrogen atom with excited state electron configuration 3s^1?

Answers

67 because it’s the lowest frequency photon

CH3-C_=CH + HCl ( 1:2) -->

Answers

CH
3

C≡CH
2mole
HCl


A
CH
3

C(Cl)
2

CH
3




Heat
aq.KOH


B
CH
3

COCH
3



write the conjugate bases of the following acids ? H₂S , HCOOH ,HSO₃¯ , HSO¯₄ , HS¯, HNO₂ ,HCN,?​

Answers

Answer:

HS(-)

HCOO(-)

SO3(2-)

SO4(2-)

S(2-)

NO2(-)

CN(-)

Explanation:

The parenthesis are the charges of the compounds. When an acid is introduced in a base, it dissociates its Hydrogens giving protons to the base. In this case, if you remove one hydrogen of a compound, you will reduce the charge of a compound since basically you're removing a positive charge from a compound. If you need to, I can explain how the thing of the charges work.

In fact, the definition of a conjugate base is a compound created when the original (an acid) compound dissacioate an atom of hydrogen (a proton) in a base.

Name three sources of atmospheric carbon dioxide.

Answers

Decomposition when an organism dies, ocean release and respiration

Carbon has a half-life of 5,730 years and you found a fossil with 4 atoms of Carbon and 12 atoms of
Nitrogen, how old would it be?

a. 0 years old
b. 5,730 years old
c. 11,460 years old
d. 17,190 years old

Answers

Answer:

D. 17,190 years old

Gaseous chlorine dioxide (ClO2) is used in bleaching flour and municipal water treatment in
500.0L containers. If these processes are performed at room temperature (22.0°C) using 52.1
moles of gas, what is the pressure? Must show calculation setup.

Answers

Taking into account the ideal gas law, the pressure is 2.52 atm.

An ideal gas is a theoretical gas that is considered to be composed of randomly moving point particles that do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.

The pressure, P, the temperature, T, and the volume, V, of an ideal gas are related by a simple formula called the ideal gas law. This equation relates the three variables if the amount of substance, number of moles n, remains constant. The universal constant of ideal gases R has the same value for all gaseous substances. The numerical value of R will depend on the units in which the other properties are worked.

P×V = n×R×T

In this case, you know:

P=?V= 500 Ln= 52.1 molesR= 0.082[tex]\frac{atmL}{molK}[/tex]T= 22 C= 295 K (being 0 C=273 K)

Replacing in the ideal gas law:

P×500 L = 52.1 moles ×0.082 [tex]\frac{atmL}{molK}[/tex] ×295 K

Solving:

P= (52.1 moles ×0.082 [tex]\frac{atmL}{molK}[/tex] ×295 K)÷ 500 L

P= 2.52 atm

Finally, the pressure is 2.52 atm.

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Please help me answer the following image! Voting for one party on a state level and the opposite party on a national level is known as _______ - __________. 50 points for 5 questions p.s if u get brainliest u get 50 moe and then u have 100 SO YAAAAAAY1.What can federal appeals courts do?Choose all answers that are correct.Overturn the decisions of the district courts.Remand cases back to lower courts.Uphold the decisions of the lower courts.Recommend cases be heard by the Supreme Court.2.Why do the losing parties in civil trials and convicted criminals seek to involve the federal appeals courts in their cases?because they feel that laws were incorrectly interpreted or applied in their casesin order to force the winning side or the prosecution to present its evidence againbecause they believe that their cases should be heard by magistrate judgesso that new appellate juries will hear the facts of their cases3.How are federal judges selected?Candidates are nominated and appointed by the Supreme Court unless the president uses the veto.Candidates are nominated by Congress and voted upon by citizens over the age of 18 in federal elections.Candidates are nominated by current federal judges and appointed by Congress if the House approves by a two-thirds majority vote.Candidates are nominated and appointed by the president if the Senate approves by a majority vote.4.What are two roles of magistrate judges?Choose exactly two answers that are correct.to hear preliminary evidence and decide if a case should be brought to trialto appoint the U.S. attorney(s) for their districtsto issue court orders, such as search warrantsto deliver rulings on major cases involving federal law5.What is the main duty of the United States Supreme Court?to sentence or parole convicted criminalsto appoint judges to lower federal courtsto hear and rule on casesto ratify or veto new laws thx UwU During the last year the value of your house decreased by 20%. If the value of your house is $265,000 today, what was the value of your house last year? Round your answer to the nearest cent, if necessary. Lucas and his brother, Max, went to the arcade yesterday. Lucas played 2 games of Rodeo Racing and 8 games of Polar Pinball. Max played 3 games of Rodeo Racing and 9 games of Polar Pinball. Which brother played the greater ratio of Rodeo Racing to Polar Pinball? The temperature on the ground during a plane's takeoff was 4*F. At 38,000 feet in the air, the temperature outside the plane was. Find the difference between these two temperatures , and enter the number only. 4 degrees * F; - 34 degrees * F This is the question in the photo above. What do you know about these two lines?y = 6x - 1y = -6x - 4A: The lines are parallel because their slopes are the same.B: The lines are perpendicular because the slopes are opposites reciprocals C: The lines are neither parallel nor perpendicular, they just intersect. (Fill in the forms of Ser ) Yo -------- tu----------el/ella/Ud.-----------nosotros---------------ellos/ellas/Uds.------- of the 400 employees,5% of them managers.How many managers does the zoo employ? I'm a father's child, a mother's child, yet no one's son. What am I? Solve the equation. -w/20=-2.5 Determine the period of the function g(x) = (cos ;) Which is the total value of the digit 4 in 34 712 What is the mass of air in room 3y-2x-4x+5x+7please help meeeeeeeeeeee 16. The K-T boundary is a layer of rock that separates the time of the dinosaurs fromtheir extinction. According to the law of superposition which of the following is true?A. Paleontologists would expect to find dinosaur bones below the K-T boundary butnot above.B. Paleontologists would expect to find dinosaur bones far away from tectonic plateboundaries where new crust is being createdC. Paleontologists would expect to find dinosaur bones above the K-T boundary butnot below.D. Paleontologists would expect to find dinosaur bones close to tectonic plateboundaries where new crust is being created Jake ran 4% miles in % of an hour. How fast did he run in one hour? What was the result of the Spanish exploration and settlement concerning the Mississippian chiefdoms of the Southeast? Please help, Which statement best completes the diagram?