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3 years ago

What is true about energy in an ordinary chemical reaction? Energy is

Chemistry

2 answers:

Lisa [10]3 years ago

4 0

The answer is statement #3.

AlekseyPX3 years ago

3 0

Energy is not created or destroyed

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Using the equations 2 Sr(s) + O₂ (g) → 2 SrO (s) ∆H° = -1184 kJ/mol SrO (s) + CO₂ (g) → SrCO₃ (s) ∆H° = -234 kJ/mol CO₂ (g) → C(

kkurt [141]

<u>Answer:</u> The $\Delta H^o_{rxn}$ for the reaction is 72 kJ.

<u>Explanation:</u>

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The given chemical reaction follows:

$2SrCO_3(s)\rightarrow 2Sr(s)+2C(s)+3O_2(g)$ $\Delta H^o_{rxn}=?$

The intermediate balanced chemical reaction are:

(1) $2Sr(s)+O_2(g)\rightarrow 2SrO(s)$ $\Delta H_1=-1184kJ$

(2) $SrO(s)+CO_2(g)\rightarrow SrCO_3(s)$ $\Delta H_2=-234kJ$ ( × 2)

(3) $CO_2(g)\rightarrow C(s)+O_2(g)$ $\Delta H_3=394kJ$ ( × 2)

The expression for enthalpy of the reaction follows:

$\Delta H^o_{rxn}=[1\times (\Delta H_1)]+[2\times (-\Delta H_2)]+[2\times (\Delta H_3)]$

Putting values in above equation, we get:

$\Delta H^o_{rxn}=[(1\times (-1184))+(2\times -(-234))+(2\times (394))]=72kJ$

Hence, the $\Delta H^o_{rxn}$ for the reaction is 72 kJ.

4 0

3 years ago

Identify the reactants in the following equation.

Lina20 [59]

Answer:

the answer is b Li + Cl2 .....

3 0

2 years ago

Solve for b if R = x(A + B)

Tatiana [17]

This is what I got. Hope it helps :)

7 0

3 years ago

Lemon juice has a pH of 2. What is the hydrogen ion concentration of lemon juice?

saw5 [17]

PH = −log [H+] = − log [5.4 × 10−3] ≈ 2.27 or 2.3.
or basically 2

7 0

3 years ago

A piece of chocolate with a mass of 8 grams melts. What is the mass of the melted chocolate?

LiRa [457]

Answer:

The mass of the melted chocolate is 8 grams.

Explanation:

When something is melted including chocolate the mass remain the same or does not change, it is only the motion of the particles that changes and this is called law of conservation of mass.

The law states that mass can neither be created nor destroyed during chemical reaction but it remain the same.

7 0

3 years ago