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Sholpan [36]
3 years ago
15

Which physical change is endothermic?

Chemistry
2 answers:
Helen [10]3 years ago
5 0

Answer: The correct option is 1.

Explanation: Endothermic reactions are the reactions in which heat is provided to break down the reactant molecules.

In option 1:

The stronger intermolecular forces between the particles in solid molecule are broken down to convert into gaseous form. Hence, some energy in the form of heat is provided to move them far apart. Therefore, it is considered as an endothermic reaction.

In option 2, 3 and 4:

All the other processes involves the formation of bonds and thus there is no need to provide any energy.

Svetllana [295]3 years ago
3 0

The physical change that is endothermic is \boxed{\left( 1 \right){\text{ C}}{{\text{O}}_{\text{2}}}\left( s \right) \to {\text{C}}{{\text{O}}_{\text{2}}}\left( g \right)}.

Further explanation:

Changes are of two types:

(A) Physical changes:

It is the process in which the physical properties of the system are affected. These changes can also be reversed by physical methods. In these kinds of changes, the molecular composition of the substance remains the same. These are reversible in nature and no new substances are formed. For example, boiling of water, chopping of wood, melting of wax are physical changes.

(B) Chemical changes:

In this change, new substances are formed by the chemical combination of the previous substances. The chemical properties of substance changes when it undergoes a chemical change. These are irreversible in nature. For example, fermentation of grapes, burning of wood, rusting of iron are chemical changes.

Endothermic reactions are those in which more energy needs to be supplied to the system than that released by it.

Exothermic reactions are those in which more energy is released by the system than that supplied to it.

(1) {\text{C}}{{\text{O}}_{\text{2}}}\left( s \right) \to {\text{C}}{{\text{O}}_{\text{2}}}\left( g \right)

In this reaction, solid carbon dioxide is converted into gaseous carbon dioxide. The strong intermolecular force of attraction in solid needs to be broken down and energy is supplied for this purpose. Hence this is an endothermic process.

(2) {\text{C}}{{\text{O}}_{\text{2}}}\left( l \right) \to {\text{C}}{{\text{O}}_{\text{2}}}\left( s \right)

In this reaction, liquid carbon dioxide is converted into solid carbon dioxide. The intermolecular forces in liquid molecules are weaker than that present in solid molecules and are broken down easily so energy is released during the process. Hence this is an exothermic process.

(3) {\text{C}}{{\text{O}}_{\text{2}}}\left( g \right) \to {\text{C}}{{\text{O}}_{\text{2}}}\left( l \right)

In this reaction, gaseous carbon dioxide is converted into liquid carbon dioxide. The intermolecular forces in gas molecules are weaker than that present in liquid molecules and are broken down easily so energy is released during the process. Hence this is an exothermic process.

(4) {\text{C}}{{\text{O}}_{\text{2}}}\left( g \right) \to {\text{C}}{{\text{O}}_{\text{2}}}\left( s \right)

In this reaction, gaseous carbon dioxide is converted into solid carbon dioxide. The intermolecular forces in gas molecules are weaker than that present in solid molecules and are broken down easily so energy is released during the process. Hence this is an exothermic process.

Learn more:

1. Which of these is an extensive property? brainly.com/question/1398514

2. Which of the phase changes is an exothermic change? brainly.com/question/1875234

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Physical and chemical changes

Keywords: physical change, chemical change, CO2, endothermic, exothermic, solid, liquid, gaseous, intermolecular forces, strong, weaker.

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Convert 7.50 grams of glucose C6H12O6 to moles
Lera25 [3.4K]

Answer:

The number of mole is 0.04167mole

Explanation:

To convert gram to mole, we need to calculate the molecular weight of the compound

C6H12O6

C - 12

H - 1

O - 16

Molecular weight = 6 * 12 + 1 *12 + 6 * 16

= 72 + 12 + 96

= 180g/mol

To covert gram to mole

Therefore,

= 7.50g/ 180g/mol

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3 0
3 years ago
Be sure to answer all parts. Consider the reaction A + B → Products From the following data obtained at a certain temperature, d
worty [1.4K]

Answer : The order of reaction with respect to A is, first order reaction.

The order of reaction with respect to B is, zero order reaction.

The overall order of reaction is, first order reaction.  

Explanation :

Rate law is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

For the given chemical equation:

A+B\rightarrow Products

Rate law expression for the reaction:

\text{Rate}=k[A]^a[B]^b

where,

a = order with respect to A

b = order with respect to B

Expression for rate law for first observation:

3.20\times 10^{-1}=k(1.50)^a(1.50)^b ....(1)

Expression for rate law for second observation:

3.20\times 10^{-1}=k(1.50)^a(2.50)^b ....(2)

Expression for rate law for third observation:

6.40\times 10^{-1}=k(3.00)^a(1.50)^b ....(3)

Dividing 1 from 2, we get:

\frac{3.20\times 10^{-1}}{3.20\times 10^{-1}}=\frac{k(1.50)^a(2.50)^b}{k(1.50)^a(1.50)^b}\\\\1=1.66^b\\b=0

Dividing 1 from 3, we get:

\frac{6.40\times 10^{-1}}{3.20\times 10^{-1}}=\frac{k(3.00)^a(1.50)^b}{k(1.50)^a(1.50)^b}\\\\2=2^a\\a=1

Thus, the rate law becomes:

\text{Rate}=k[A]^1[B]^0

\text{Rate}=k[A]

Thus,

The order of reaction with respect to A is, first order reaction.

The order of reaction with respect to B is, zero order reaction.

The overall order of reaction is, first order reaction.

7 0
3 years ago
How many moles of hydrogen gas will be produced if 5.00 moles of zinc reactions with an excess amount of sulfuric acid
harkovskaia [24]

Answer:

Moles of Hydrogen produced is 5 moles

Explanation:

The balanced Chemical equation for reaction between zinc and sulfuric acid is :

Zn(s) + H_{2}SO_{4}(aq) \rightarrow ZnSO_{4}(aq) + H_{2}(g)

This equation tells that ; when  1 mole of Zn react with 1 mole of sulfuric acid, it produces 1 mole of zinc sulfate and 1 mole of hydrogen.

Since sulfuric acid is in excess so Zinc is the limiting reagent

(Limiting reagent : Substance which get consumed when the reaction completes, limiting reagent helps in predicting the amount of products formed)

Limiting reagent (Zn) will decide the amount of Hydrogen produced

Zn(s) + H_{2}SO_{4}(aq) \rightarrow ZnSO_{4}(aq) + H_{2}(g)

1\ mole\ zinc\rightarrow 1\ mole\ H_{2}

So,

5\ mole\ zinc\rightarrow 5\ mole\ H_{2}

Hence moles of Hydrogen produced is 5 moles

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If you are calculating the grams to mL ratio, you are trying to find the object’s…
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Answer:

Density

Explanation:

The ratio of mass to the volume of an object is called its density. Unit of mass is grams and that of volume is mL.

Density = mass/volume

\text{Density}=\dfrac{\text{grams}}{\text{mL}}\\\\=\text{grams/mL}

If you are calculating the grams to mL ratio, it means that we are trying to find the object's density.

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As of right now, which of the following forms of nuclear power is the most feasible for human use?
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