Which of the following statements is true about exothermic reactions?

Answers

Answer 1

Answer:

An Exothermic Reaction , gives off more heat, and a little energy to its surroundings.

this can helps us figure out that the answer is , C, More heat is given off into its products.

Explanation:


Related Questions

HELP ASAP DUE IN 5 MINUTES WILL GIVE BRAINLIEST
Energy is conserved within a system, meaning that forms of energy are either transferred or transformed as they interact with objects. Which of the statements below correctly describe how energy is transferred or transformed in daily life?
Group of answer choices

Kinetic energy transforms into thermal energy when a heating pad is turned on.

Electrical energy is transferred into light energy so that a flashlight generates light when it’s turned on.

Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street.

Nuclear energy is transferred to electrical energy to provide electricity for our homes.

Answers

Answer:

i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right

Explanation:

Answer:

i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right

Explanation:

Help me if you know this pleaseeee

Answers

Answer:

help you with what?

Explanation:

a) Calculate the standard reaction entropy for the combustion of methane to carbon dioxide and liquid water at 298 K. b) Calculate the standard reaction entropy for the hydrolysis of liquid water to form oxygen and hydrogen gas. c) Do your results in (a) and (b) agree with the general rule that reaction entropies are positive if there is a net formation of gas in a reaction, and negative if the is a net reduction of gas?

Answers

Answer: (a) [tex]\Delta S^{0}[/tex] = - 242.2J/K.mol

              (b) [tex]\Delta S^{0}[/tex] = 163.34J/K.mol

              (c) Yes

Explanation: Entropy is the measure of randomness or disorder of a system. Standard Entropy has the symbol [tex]S^{0}[/tex].

Mathematically, Entropy is defined as

[tex]\Delta S^{0}=\Sigma S^{0}(products)-\Sigma S^{0}(reagents)[/tex]

Each substance has its own entropy value.

(a) Combustion of Methane:

[tex]CH_{4}+2O_{2}[/tex] ⇒ [tex]CO_{2}+2H_{2}O[/tex]

Using standard entropy table, entropy will be:

[tex]\Sigma S^{0}(products)=214+2(69.91)[/tex] = 353.8

[tex]\Sigma S^{0}=186.264+2(205.138)[/tex] = 596.54

[tex]\Delta S^{0}=[/tex] 353.8 - 596.54

[tex]\Delta S^{0}=[/tex] - 242.2

Standard Entropy for combustion of methane is [tex]\Delta S^{0}=[/tex] - 242.2 J/K.mol.

(b) Hydrolysis of Water:

[tex]H_{2}O_{(l)}[/tex] ⇒ [tex]H_{2}_{(g)}+1/2O_{2}_{(g)}[/tex]

[tex]\Sigma S^{0}(products)=130.684+0.5(205.138)[/tex] = 233.253

[tex]\Sigma S^{0}(reagents)=69.91[/tex]

[tex]\Delta S^{0}=[/tex] 233.253 - 69.91

[tex]\Delta S^{0}=[/tex] +163.34

Standard Entropy for hydrolysis of water is [tex]\Delta S^{0}=[/tex] + 163.34 J/K.mol

(c) Yes, the results prove the general rule: Reactions Entropies are positive for net formation of gas and negative for net reduction of gas. This happens because, as entropy is the measure of disorder, the entropy for gases are greater than for liquids and solids. So, when there is formation of a gas, Entropy increases and when there isn't, entropy decreases.

Solids, liquids and gases are all
considered to be forms of matter.
Each of these take up space and also
exhibit what other significant
characteristic?
A. color
B. smell
C. texture
B. mass

Answers

Answer:

mass

Explanation:

hope this helps you!!

I want to say texture but I’m not 100%

Conservation of mass to balance the following reaction. Na2S+ KI= NaI+ K2S

Answers

Answer:

1+2=2+1 is the answer for the question

What are the respective central-metal oxidation state, coordination number, and overall charge on the complex ion in Na2[Cr(NH3)2(NCS)4]?
A) +3; 6; -1
B) +2; 6; -2
C) +1; 6; -2
D) +3; 6; +1

Answers

Answer:

B) +2; 6; -2

Explanation:

In order to know what the coordination number is, all we need to do is to count the number of ligands present in the coordination sphere. Coordination number refers to the number of ligands in the coordination sphere of a given complex. The coordination number here is 6.

The counter ion here is 2Na+. It means that the overall charge on the complex must be -2 because the magnitude of charge on the complex ion is exactly balanced by the number of counter ions.

The charge on the metal (x) must now be;

x + 0 + 4(-1) = -2

x - 4 = -2

x = -2 + 4

x = +2

Note that NH3 is designated as zero because it is a neutral molecule. Each NCS^- ion has a charge magnitude of -1.

what is a common use for electromagnets

Answers

Answer:

Electromagnets are widely used as components of other electrical devices, such as motors, generators, electromechanical solenoids, relays, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment.

Explanation:

Hope this helps :)

(didn't get this from the internet)

PLEASE HELP

is this a chemical or physical change???

Answers

Answer:

Chemical, cause physical are changes affecting the form of a chemical substance, but not its chemical composition. This doesn't affect the substance but the composition.

Explanation:

chemical change! answer: chemical change!

step by step explanation:

Experiment: Turn on Show electronegativity. Electronegativity (EN) describes how strongly an atom attracts a pair of shared electrons. The higher the EN value, the greater the tendency of an atom to hold onto electrons in a bond and become negatively charged. Electronegativity difference is found by subtracting the EN value of one atom from another. Choose two nonmetals with a small (or no) EN difference between them. Click Play. What happens to the shared electrons in this bond

Answers

Answer:

See explanation

Explanation:

If we take two nonmetals with little or no electronegativity difference between them, the shared electrons are not attracted greatly towards any of the bonding atoms. In other words, the shared electrons remain equidistant between the nuclei of the two bonding atoms.

The bond is nonpolar since polarity is introduced into covalent bonds by a significant difference in electronegativity of the bonding atoms.

Which compound would you expect to be soluble in the nonpolar solvent carbon disulfide?

Answers

Answer:

hexane C6H14

IS YOUR ANSWER

Explanation:

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bond energy is the greatest for?​. a: Ch4 b: O2 c: N2 d: Cl2

Answers

It's answer is c. N2

The maximum bond energy is of N2 because N2 molecule is formed by 3 covalent bonds and O2 molecule is formed by 2 covalent bonds.

Hope it helps :)

Consider the amino acid below, which is called alanine

Which atoms give the amino acid its unique chemical and physical properties?
A.the CH3 group
B. the amino groups
C. the oxygen atom
D. the hydrogen atom

Answers

A- the CH3 group

Just answered

Answer:

A) the CH3 group

Explanation:

How many grams of oxygen, O2 are produced if 52.0g of potassium chlorate, KClO3, decomposes? (The molar mass of O2 = 32 g/mol and the molar mass of KClO3 = 122.4 g/mol).

Answers

Answer:

20.39 g of O2.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2KClO3 —> 2KCl + 3O2

Next, we shall determine the mass of KClO3 that decomposed and the mass of O2 produced from the balanced equation. This is illustrated below:

Molar mass of KClO3 = 122.4 g/mol

Mass of KClO3 from the balanced equation = 2 × 122.4 = 244.8 g

Molar mass of O2 = 32 g/mol

Mass of O2 from the balanced equation = 3 × 32 = 96 g

Summary:

From the balanced equation above,

244.8 g of KClO3 decomposed to produce 96 g of O2.

Finally, we shall determine the mass of O2 produced from the decomposition of 52 g of KClO3. This can be obtained as follow:

From the balanced equation above,

244.8 g of KClO3 decomposed to produce 96 g of O2.

Therefore, 52 g of KClO3 will decompose to produce =

(52 × 96)/244.8 = 20.39 g of O2.

Thus, 20.39 g of O2 is produced.

Suppose that all you know about a certain electron is that its principal quantum number is 3. What are the possible values for the other four quantum numbers

Answers

Answer:

Other possible quantum numbers would be.

A). When n = 3,

I = 0,

m1 = 0

ms = +1/2 or -1/2

B). When I = 1,

m1 = -1 or +1

ms = +1/2 or -1/2

C). When I = 2

m1 = -2,-1,0,1 or 2

ms = +1/2 or -1/2.

4. Kendrick drags his bat out to play baseball. which statement best describes the science of what he did?
O Kendrick would use less energy if he dragged the bat faster.


Kendrick did not have to work to move the bat because he dragged it.


Kindrick gave the bat potential energy.


Kindrick gave the bat kinetic energy.

Answers

Explanation:

Kendrick gave the bat potential Energy

(Numerical problems) A car is running with the velocity of 72km/h. What will be it's velocity after 5s if it's acceleration is -2m/s square​

Answers

The car's velocity after 5s : 10 m/s

Further explanation

Given

velocity=v=72 km/h=20 m/s

time=t = 5 s

acceleration=a = -2 m/s²

Required

velocity after 5s

Solution

Straight motion changes with constant acceleration

[tex]\tt v_f=v_i+at[/tex]

vf=final velocity

vi = initial velocity

Input the value :

[tex]\tt v_f=20+(-2).5\\\\v_f=20-10\\\\v_f=10~m/s[/tex]

The car is decelerating (acceleration is negative) so that its speed decreases

Answer:

The Velocity after 5s if its acceleration is -2m/s is 10 m / s.

Explanation:

The motion equation is given by v = u + a x t.

Initial speed (u) is equal to 72 km/h.

Acceleration (a) equals 2 m/s2.

Time (t) = 5s.

Changing the initial velocity's direction from km/h to m/s:

1 km/hr is equal to 1000 m/3600 s/5/18 m/s.

velocity (u) is equal to 72 x (5 / 18) m/s, or 20 m/s.

The motion equation can be used to calculate final velocity.

To change values in the equation of motion, do the following:

Final Velocity (v) = u + a x t

v = u + a x t

v = 20 m/s + (-2 x 5) m/s

v = (20 - 10)m/s v = 10 m/s

As a result, the car's speed after 5 seconds will be 10 m/s.

To know more about Velocity,

brainly.com/question/24567267

brainly.com/question/22038177

Create an atom diagram using the Bohr model. Directions Choose three elements from the following list. Use a periodic table to determine the number of protons, neutrons, and electrons. Draw a diagram of each element you have selected. Use a separate piece of paper for each element. Be sure your drawing is neat, legible, and accurate. Use this data table to record information about each element. Element #1 Element #2 Element #3 Element #4

Answers

Answer:

Explanation:

proposed an early model of the atom as a central nucleus containing protons and neutrons being orbited by electrons in shells. As previously discussed, there is a connection between the number of protons in an element, the atomic number that distinguishes one element from another, and the number of electrons it has. In all electrically-neutral atoms, the number of electrons is the same as the number of protons. Each element, when electrically neutral, has a number of electrons equal to its atomic number.

Answer:

You can check diagram with number of proton neutron and electrons

Explanation:

which event would most likely lead to a thunderstorm g i v i n g b r a i n l e s i t

Answers

Answer:

A

Explanation:

I took a test like this and my teacher said this was right so ye. hopefully I remembered correctly if its wrong im sorry ;C

Answer: A

Explanation: A thunderstorm forms when warm, moist air rises into cold air. Hope this helps. :)

When the volume of a gas is
changed from 3.6 L to 15.5 L, the
temperature will change from
°C to 87°C.
Assume that the number of moles and the
pressure remain constant.
Be sure to notice that temperatures are
given in °C!

Answers

Answer:

-189.55°C

Explanation:

Given data:

Initial volume of gas = 3.6 L

Final volume of gas = 15.5 L

Initial temperature = ?

Final temperature = 87°C (87+273 = 360 K)

Solution:

The given problem will be solve through the Charles Law.

According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume  

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

T₁  = V₁T₂  /V₂

T₁   = 3.6 L × 360 K / 15.5 L

T₁   = 1296 L.K / 15.5 L

T₁  = 83.6 K

Kelvin to °C:

83.6 K - 273.15 = -189.55°C

In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide?
A. one
B. two
C. three
D. four
E. none

Also, state why.

Answers

Answer:

E

because it forms the ionic bond but not covalent.

how can use a BIPHASIC LIQUIDS​

Answers

Answer:

BIPHASIC LIQUIDS are used ear cleaning, to softening the wax so that mild infections can be treated.

Explanation:

BIPHASIC LIQUIDS are liquids that contain two immiscible phases, one is suspension and the other is emulsion. In suspension, the finely solid are dispersed in a liquid or semi solidwhich is use for medicament

The emulsion consist of immiscible liquids, one is dispersed in globules.

They are used ear cleaning, to softening the wax so that mild infections can be treated.

(plsss help meh.) Describe how you could find the density of a gold crown.

Answers

Answer:

Below! ;)

Explanation:

The formula for finding density is:

Mass/Volume

So for example I have a cube, it has a mass of about 20 grams (not weight) and it's dimensions are about an inchxinchxinch. So basically it is a 20 gram cubic inch cube.

So to find it's density I have to divide mass(=20)/Volume(=1 inch^3). or simplified, 20 ÷ 1 = 20

So the density of my cube is 20..

Hope this helps!

Have a nice day!

If you find my answer helpful

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The table shows four reactions.
Reactions
Reaction Equation
C₃ H8+ 50₂ 3C02 + 4H20
2Ca + O2- 2CaO
AgNO3 + NaCl
AGCI + NaNO3
CH3COOH + 202 - 2CO2 + 2H20
4
Which of the above reactions is an example of combustion of an Inorganic substance? (5 points)

Answers

Answer: 2

Explanation:

A combustion reaction must include O2 as a reactant.

An inorganic substance almost never includes carbon.

So, by process of elimination:

1. Carbon is a reactant = probably not

2. Has O2, no carbon = yes

3. O2 is not a reactant = no

4. Carbon is a reactant = probably not

An example of the combustion of an inorganic substance is:

2 Ca + O₂ ⇒ 2 CaO

We have 4 reactions and we want to determine which is an example of combustion of an inorganic substance.

What is combustion?

A combustion reaction is a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat.

What is the difference between organic and inorganic substances?

Organic substances always contain carbon while most inorganic substances do not contain carbon.

Let's consider the following reactions.

C₃H₈ + 5 O₂ ⇒ 3 CO₂ + 4 H₂O

This is a combustion reaction but C₃H₈ is an organic substance.

2 Ca + O₂ ⇒ 2 CaO

This is an example of the combustion of an inorganic substance.

AgNO₃ + NaCl ⇒ AgCI + NaNO₃

This is not a combustion reaction.

CH₃COOH + 2 O₂ ⇒ 2 CO₂ + 2 H₂O

This is a combustion reaction but CH₃COOH is an organic substance.

An example of the combustion of an inorganic substance is:

2 Ca + O₂ ⇒ 2 CaO

Learn more about combustion here: https://brainly.com/question/4155165

Which of the following is an essential condition for a combustion reaction?

A - Oxygen is a product.
B - Oxygen is a reactant.
C - Carbon dioxide is a product.
D - Carbon dioxide is a reactant.

Answers

Answer:

oxygen is a reactant.

Explanation:

Combustion is the reaction with atmospheric oxygen forming carbon dioxide and water. Therefore, the essential condition is option B oxygen as a reactant.

What is combustion?

Combustion is a type of reaction in which a molecule or compound reacts with atmospheric oxygen producing carbon dioxide and water. Combustion reaction is exothermic thus, evolves heat during reaction.

The general chemical equation for a combustion reaction can be written as:

[tex]\rm M + nO_{2} \rightarrow xH_{2}O + y CO_{2}[/tex]

Where, M be a reactant.

Combustion is an aerobic process that is only taking place in presence of oxygen. Hydrocarbon gases easily undergo combustion forming heat energy and they are used as fuels propellants.

To find more on combustion, refer here:

https://brainly.com/question/15117038

#SPJ2

Q 16.1: Select the first step in the Wittig reaction. A : The alkyltriphenylphosphonium halide is deprotonated by a base to make a phosphorus ylide. B : The phosphorus ylide reacts with the aldehyde or ketone to make an oxaphosphetane. C : Triphenylphosphine attacks the alkyl halide to produce an alkyltriphenylphosphonium halide. D : The oxaphosphetane decomposes to form the alkene and triphenylphosphine oxide.

Answers

Answer:

The phosphorus ylide reacts with the aldehyde or ketone to make an oxaphosphetane.

Explanation:

The Wittig reaction is a reaction that occurs between a phosphorus ylide and an aldehyde or ketone. The final products are an alkene and triphenyl phosphine oxide.

The first step in the reaction is the attack of the phosphorus ylide on the aldehyde or ketone. This is followed by attack of oxygen on phosphorus to form a [2+2] cycloaddition product (oxaphosphetane)  which  decomposes to form the alkene and triphenylphosphine oxide.

PLEASE HELP WILL GIVE BRAINLIEST

Answers

Answer:

Coefficients represents no of moles while subscripts represent no of atoms.

Answer:

Coefficients came before formula . Example = 4CO means there are 4 molecules of carbonmonooxide.

Subscripts came after and below the formula . Example = Oxygen gas in which 2 is a subscript which means there are 2 atoms of Oxygen in 1 molecule of Oxygen i.e. oxygen gas

ANSWERS PLEASE HELP 20 MINUTES LEFT????!!!!?!!???

Answers

Answer:

Explanation:

b

Show the calculation of the molality of a solution made by dissolving 15.9 grams of Ca3(PO4)2 in 400 grams of water.

Answers

The molality of a solution : 0.128 m

Further explanation

Given

15.9 g of Ca3(PO4)2 in 400 grams of water.

Required

The molality

Solution

molality = mol solute / kg solvent

solute= Ca3(PO4)2(MW=Molecular Weight: 310.2 g/mol)

mol solute :

[tex]\tt \dfrac{15.9}{310.2}=0.0512[/tex]

The molality :

[tex]\tt \dfrac{0.0512}{0.4~kg}=0.128~m[/tex]

Which chemical equation below is not balanced?
- 3 MgSO4 + 2 Nag PO4 → Mgs (PO4),+3 Na, S04
- 2 NaOH + HNO, → NaNO, + 2 H,0
- CH12 O6 4 6O2 → 6 CO, + 6 H,0
- HBr AGNO, → HNO, + AgBr

pic if needed ;)

Answers

Answer:

B

Explanation:

The second one is not balanced correctly.

2 NaOH + 2HNO3 → 2NaNO3 + 2 H20

I didn't notice this before but it can be balanced without the twos.

 NaOH + HNO3 → NaNO3 +  H20

It was still wrong. It needed to have the twos removed, not 2 more added. Adding two more isn't wrong, but it should be balanced without 2s if at all possible.

Which force keeps the planets from floating off into space?

Earth’s gravity
the Sun’s gravity
the moon’s gravity
Milky Way’s gravity

Answers

Answer:

Suns gravity

Explanation:

Answer: 2021

B

The Sun's gravity

Explanation: Just took the big test

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