If heat is required for a chemical reaction to occur, from where does the energy come?

Answers

Answer 1

Answer:

Chemical energy is energy stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place. Usually, once chemical energy has been released from a substance, that substance is transformed into a completely new substance.

Explanation:


Related Questions

The vaporization of Br2 from the liquid to the gas state requires 7.4 kcal/mol. write a reaction showing heat as a product or reactant

Answers

Answer:

Br₂(l) + ΔV → Br₂(g)

Explanation:

When a chemical or phase change occurs during a chemical process some heat is absorbed or released. For the process of vaporization of a substance, the heat (Usually required) is ΔV (How many energy is required for the process occurs).

In the vaporization of Br2 there are required 7.4kcal/mol, Δv. The reaction is:

Br₂(l) + ΔV → Br₂(g)


Convert 3564 to Scientific Notation:
*

Answers

Answer:

3564 = 3.564 x 10^3

Explanation:

i.e expresing the value in standard form.

How does energy (heat) flow in the ocean?​

Answers

Answer:

There is a connection between the ocean and the atmosphere (they work together to move heat and fresh water across the globe) . Heat can be  transferred between the surface of a sea or ocean and the atmosphere through ;

RadiationConvection,Turbulent heat exchange Evaporation of waterCondensation of water vapor above the sea or ocean .

Explanation:

Which properties of grains determine the texture of rocks? Check all that apply.

feel

pattern

color

shape

size


I will mark Brainlyest

Answers

Shape the correct answer

Answer:

color shape and size

Explanation:

Describe the function of a cilia.

Answers

Answer:

hope it helps..

Explanation:

'Motile' (or moving) cilia are found in the lungs, respiratory tract and middle ear. ... These cilia have a rhythmic waving or beating motion. They work, for instance, to keep the airways clear of mucus and dirt, allowing us to breathe easily and without irritation.

Answer: to keep airway clear of mucus and dirt allowing us to breathe easy

Explanation:

Help me lol
I’ll give branliest if two people answer

Answers

Answer:

I think all of the above

Explanation:

Put as brainliest if you wish

it is all of the above

Write a balanced equation for each of the acid-base reaction given below.a. Aqueous sulfuric acid with aqueous potassium hydroxide.

Answers

Answer:

H2SO4 + 2KOH => K2SO4 + 2H2O

Explanation:

The acid-base reaction is a type of chemical reaction that involves the exchange of hydrogen ions.

The acid-base reaction between aqueous sulfuric acid ( H2SO4 ) and aqueous potassium hydroxide (KOH) is a neutralization reaction that results in potassium sulfate and water.

sulfuric acid + potassium hydroxide => potassium sulfate + water

So, the balanced equation for this reaction is as follows:

                  H2SO4 + 2KOH => K2SO4 + 2H2O

Hence, the correct answer is "H2SO4 + 2KOH => K2SO4 + 2H2O".

Why do you think the hot red water sank to the bottom?

Answers

Answer:

i did this in school :) but Hot water will rise to the top because it is less dence and cold water will sink to the bottom because it is more dence

Explanation:

The red water is more dense then the water on top so it sinks to the bottom

PLEASE HELP ME!!
I am smaller than Rb and bigger than Na but we are in the same family.
H
K
N
Cs
Is it easier to remove an electron from Mg or from Cl?
Mg
Cl

Answers

Answer: K and Mg

Explanation:

The first one refers to the atomic radius and increases going down and to the left on the periodic table. K is in between Rb and Na.

3.
What are valence electrons? How do you quickly determine the number of valence electrons an
atom has?

Answers

Answer:

Electrons that arent electrons

Explanation:

I teach chem

Answer:

Valence electrons are the electrons found in the highest and main energy level of the atom, being these responsible for the interaction between atoms of different species or between atoms of the same species. You can quickly determine these by looking at a periodic table like this one... Which is where the roman numbers come in and show the valence electrons. (THIS TABLE IS IN SPANISH, I hope you still recognize the symbols.) :))

Enter your answer in the provided box.
A sample of chlorine gas is confined in a 7.17-L container at 491 torr and 37.0°C.
How many moles of gas are in the sample?
mol Cl2

Answers

Answer: 0.182 mols Cl2
Hope this helps! :)

Each orbit of an atom contains a set number of..........

Answers

Answer:

I'm pretty sure it's electrons

How for way is the Neptune from the sun

Answers

2.8 billion miles which can be said as 4.5 billion kilometres
hope this helps x
Neptune is 4469 million km away from the sun . The above answer is from my social studies textbook

Calculate the number of molecules in 2.00 moles H2S.
Express your answer numerically in molecules.

Answers

Answer:

The answer is

1.204 × 10²⁴ molecules

Explanation:

The number of molecules can be found by using the formula

N = n × L

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

N = 2 × 6.02 × 10²³

We have the final answer as

1.204 × 10²⁴ molecules

Hope this helps you

An element is lustrous, brittle, and silver colored. What type of element is it
Metal
Metalloid
Non Metal
Other
Will give brainlist

Answers

Metal, since some metals can be brittle

In chemical reactions, what does the law of conservation of mass mean?
Group of answer choices

Matter is not created nor destroyed.

The total mass of the products is greater than the total mass of the reactants.

The total mass of the reactants is less that the total mass of the products.

Matter is not changed.

Answers

Answer

The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.

why some metals are more dense than others

Answers

This is due to the tightly packed crystal lattice of the metallic structure. The larger the amounts of delocalized electrons, the stronger the metallic bonds are.

which type of wave shows energy transmitted in a definite direction and with a definite speed?

Answers

The answer is traveling wave

HELPPP

Which of the following pairs of elements is most likely to permanently transfer one or more electrons to the
other element?
a. Chlorine and phosphorus
b. Iron and bromine
c. Tin and lead
d. Nitrogen and oxygen

Answers

B is the answer I think hope this helps


In chemistry lab, a student measured the density of liquid ethanol is 0.789 g/mL. Represent its density in units of 1b /in3? (2.54 cm = 1 in., 2.205 lb = 1 kg)
A. 9.09 x 10+ 1b / in
B.4.42 x 10-1b / in?
OC.2.85 x 10-2 16 / in
D. 0.106 16 / in?
O E.5.86 x 10" 16/in3​

Answers

Answer:

Option C is correct option = 2.85×10⁻² lb/in³

Explanation:

Given data:

Density in g/mL = 0.789

Density in lb/in³ = ?

Solution:

It is given that,

2.54 cm = 1 in

2.205 lb = 1 kg   thus,

1 mL = 1 cm³

0.789 g/cm³ × 1 kg/ 1000 g × 2.205 lb/1 kg × (2.54 cm / 1in)³

2.85×10⁻² lb/in³

The density of liquid ethanol is 0.789 g/mL, which is equivalent to 0.0285 lb/in³.

A student measured the density of liquid ethanol to be 0.789 g/mL and we want to convert it to lb/in³. We will need a series of conversion factors.

What is a conversion factor?

A conversion factor is an arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.

Step 1: Convert 0.789 g/mL to lb/mL

We will use the following conversion factors:

1 kg = 1000 g.1 kg = 2.205 lb.

0.789 g/mL × (1 kg/1000 g) × (2.205 lb/1 kg) = 1.74 × 10⁻³ lb/mL

Step 2: Convert 1.74 × 10⁻³ lb/mL to lb/in³

We will use the following conversion factors:

1 mL = 1 cm³.1 in = 2.54 cm.

1.74 × 10⁻³ lb/mL × (1 mL/1 cm³) × (2.54 cm/1 in)³ = 0.0285 lb/in³

The density of liquid ethanol is 0.789 g/mL, which is equivalent to 0.0285 lb/in³.

Learn more about unit conversion here: https://brainly.com/question/13016491

All of the following changes to a metal are physical changes except_____.


bending

melting

rusting

polishing

Answers

Answer:

D)Polishing..

Answer:

Wouldn't it be rusting

Explanation:

Melting and bending are physical changes so is polishing. so rusting is the only choice, for metal to rust wouldn't it need a chemical change.

solve this very easy choose option fast​

Answers

Answer:

i think its alcohol and salt because they put salt on the ground to dissolve the snow so what I think is its alcohol and salt cuz they both look like they would evaporate pretty easy and alcohol evaporates really really easy so I think it's alcohol and salt because salt May absorb it or something I don't know but yeah

Answer: alcohol and iodide

Explanation:

A 10.151 g sample of window cleaner containing ammonia was diluted with 39.466 mL of water. Then 4.373 g of solution was titrated with 14.22 mL of 0.1063 M HCl to reach a bromocresol green end point. Find the weight percent of NH3 (FM 17.031) in the cleaner.

Answers

Answer:

2.878 (w/w)%

Explanation:

The reaction of NH3 with HCl is:

NH3 + HCl → NH4Cl

That means 1 mole of ammonia reacts per mole of HCl. The moles of HCl that reacts = Moles of ammonia are:

14.22mL = 0.01422L * (0.1063mol HCl / L) = 0.001512 moles HCl = Moles ammonia

In mass:

0.001512 moles NH3 * (17.031g / mol) = 0.02574g of NH3 in the solution.

The concentration in weight percent of the diluted solution is:

0.02574g of NH3 / 4.373g * 100 = 0.5887 (w/w)%

This is the concentration of the diluted solution that was diluted from 10.151g to 10.151g + 39.466g = 49.617g

-Assuming density of water = 1g/mL-

The solution was diluted:

49.617g / 10.151g = 4.888 times.

That means the concentration of NH3 in the original cleaner is:

0.5887 (w/w)% * 4.888 =

2.878 (w/w)%

What is matter?
A.
Anything that has energy
B.
Anything that changes volume
C.
Anything that takes up space
D.
Anything that produces heat
a b c or d no bull

Answers

Answer:

C. Anything That Takes Up Space.

Explanation:

C2H6O
Percent Composition with work shown

Answers

Answer:

50 percent

Explanation:

percentage

(3.1 x 10^3) (1.00 x 10^7) =

Answers

Answer:

(3.1 x 10^3) (1.00 x 10^7) = 31000000000

In Natural selection, individuals whose unique characteristics are well-suited for an environment tend to survive and produce more offspring. true or false? i need this help!right now!

Answers

Answer:

True

Explanation:

True. If an animal has attributes to it that help it survive better in an environment, it will survive better than its counterparts who do not have this attribute. More survival = More offspring

Answer:

True.

Explanation:

It's called survival of the fittest. Animals are genetically supposed to be well suited to their environment and if they aren't, they die out.

A deck of cards has dimensions 8.9cm x 5.72cm x 1.82 cm. What is the volume of the deck in cubic centimeters?

Answers

Answer:

92.65256 cm^3

Explanation:

To find this, we can simply multiply all three dimensions to get the answer in cubic centimeters, and we get the answer above. If you want to be more specific, we can go by the sigfig rule and the answer would be rounded to 93 cm^3.

Subscripts are used in a chemical formula to show the number of atoms of each element.
True or False.
If endothermic means that the temperature increases and exothermic means it decreases, it 64 degrees to 64 degrees (it stayed the same) endothermic or exothermic?

Answers

False exothermic creates heat endothermic create cold

Answer:

The answer is none of them.

Explanation:

I did the study guide...Also, if it has no change, it is neither.

how many moles in 1.505x10^23 Na atoms

Answers

Answer:

The answer is 0.25 moles

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question

N = 1.505 × 10²³ Na atoms

We have

[tex]n = \frac{1.505 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{1}{4} \\ [/tex]

We have the final answer as

0.25 moles

Hope this helps you

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