What do the numbers listed for an element on the periodic table represent?

For the following systems at equilibrium C: CaCO3(s) ⇌ CaO(s)+CO2(g) ΔH=+178 kJ/mol D: PCl3(g)+Cl2(g) ⇌ PCl5(g) ΔH=−88 kJ/mol cl

Rama09 [41]

Explanation:

C: $CaCO_3(s)\rightleftharpoons CaO(s)+CO_2(g)$ ΔH=+178 kJ/mol

For an endothermic reaction, heat is getting absorbed during a chemical reaction and is written on the reactant side.

$A+\text{heat}\rightleftharpoons B$

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle. This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

Treat heat as a reactant and on increasing a reactant at equilibrium, shifts the reaction in the forward direction.

Increase temperature → increase in heat → forward direction

Decrease temperature → decease in heat → backward direction

System C - Increase temperature : Reaction will move forward

System C - Decrease temperature : Reaction will move backward

D: $PCl_3(g)+Cl_2(g)\rightleftharpoons PCl_5(g)$ ΔH=−88 kJ/mol

The total enthalpy of the reaction comes out to be negative .

The temperature of the surrounding will increase.

For an exothermic reaction, heat is released during a chemical reaction and is written on the product side.

$A\rightleftharpoons B+\text{ heat}$

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle. This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

Treat heat as a product and on increasing a product at equilibrium, shifts the reaction in the backward direction.

Increase temperature → increase in heat → backward direction

Decrease temperature → decease in heat → forward direction

System D - Increase temperature : Reaction will move backward

System D - Decrease temperature : Reaction will move forward

7 0

2 years ago

How many molecules are contained in 125 grams of water, H20?

sergejj [24]

Answer:

18,01528

Explanation:

8 0

2 years ago

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Which of the following statements correctly characterizes the subatomic particle

vichka [17]

Answer:

Its mass is about the same as that of a proton

Explanation:

4 0

2 years ago

What path does water take as it collects salt while flowing to the ocean?

vichka [17]

Answer:Ocean water is constantly moving, and not only in the form of waves and tides. Ocean currents flow like vast rivers, sweeping along predictable paths. Some ocean currents flow at the surface; others flow deep within water. Some currents flow for short distances; others cross entire ocean basins and even circle the globe.

By moving heat from the equator toward the poles, ocean currents play an important role in controlling the climate. Ocean currents are also critically important to sea life. They carry nutrients and food to organisms that live permanently attached in one place, and carry reproductive cells and ocean life to new places.

Explanation:

i got this off my chemistry sight.. your welcome

6 0

2 years ago

How are the following aspects of a reaction affected by the addition of a catalyst? 1) activation energy of the reverse reaction

snow_tiger [21]

These are four questions and four answers.

Answers:

1) activation energy of the reverse reaction

b. Decreased

2) Rate of the forward reaction

a. Increased

3) Rate of the reverse reaction

a. Increased

4) Activation energy of the forward reaction

b. decreased

Explanation:

Activarion energy is the energy required by the reactants to form the intermediate transition state and become products.

Catalysts are substances that change the path of the chemical reactions, lowering the activation energy, and thus speeding up the rate of the reactions, since the products can reach the new lower activation energy faster.

The equilibrium reactions are the chemical process in which two reactions, the forward and the reverese reactions, occur simultaneously and at the same rate. The equlibrium reactions may be represented by:

A ⇄ B

Where A → B is the direct or forward reaction, and A ← B is the reverse reaction (note the inversed arrow, from right to left).

For the direct reaction A represents the reactants and B represents the products. On the other hand, B represents the reactants and A represents the reactants of the reverse reaction and A. This, is A is the reactant of the forward reaction and the product of the reverse reaction, while B is the reactant of the reverse reaction and the product of the forward reaction.

Since, the addition of a catalyst lowers the activation energy of the process, the new activation energy is lower for both the forward and the reverse reaction, meaning that:

1. The activation energy of the reverse reaction is decreased (option b. of the first question)

2. The rate of the forward reaction is increased (option a. of the second question)

3. The rate of the reverse reaction is increased (option a. of the third question).

4. Activation energy of the forward reaction is decreased (option b. of the fourth question).

In summary, the addition of a catalyst decreases the activation energy for both forward and reverse reactions, and increases the rate of both forward and reverse reactions.

3 0

2 years ago

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