Help with this please !

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

What mass of zinc (molar mass 65.4 g moll) does it take to produce 0.50 mole of H2(g)?

Hatshy [7]

Answer:

32.7 g of Zn

Explanation:

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

Zn + 2HCl —> ZnCl₂ + H₂

From the balanced equation above,

1 mole of Zn reacted to produce 1 mole of H₂

Next, we shall determine the number of mole of Zn required to produce 0.5 mole of H₂. This can be obtained as follow:

From the balanced equation above,

1 mole of Zn reacted to produce 1 mole of H₂.

Therefore, 0.5 mole of Zn will also react to produce to 0.5 mole of H₂.

Thus, 0.5 mole of Zn is required.

Finally, we shall determine the mass of 0.5 mole of Zn. This can be obtained as follow:

Mole of Zn = 0.5 mole

Molar mass of Zn = 65.4 g/mol

Mass of Zn =?

Mass = mole × molar mass

Mass of Zn = 0.5 × 65.4

Mass of Zn = 32.7 g

Thus, 32.7 g of Zn is required to produce 0.5 mole of H₂.

4 0

3 years ago

Describe the reason why a reaction between two substances comes to an end.

Shtirlitz [24]

Answer: The process by which a particular substance or different substances are transformed to another is called as Chemical Reaction.One reason, in the case of reversible reactions could be that the reaction reached equilibrium before the reaction was complete.Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products.The concentration of reactants decreases as the reaction proceeds and at last their concentration comes to an end. Hence, the reaction stops too. If two reactants are being reacted, then the reactant which is in limited amount will consume first and will result in the termination of reaction.The usual reason is that one (or more) of the reactants gets used up.

Hope that was helpful.Thank you!!!

8 0

3 years ago

Type the correct answer in the box. Express your answer to three significant figures. Calcium nitrate reacts with sodium phospha

RoseWind [281]

6.07 grams is the theoretical yield of calcium phosphate (Ca₃(PO₄)₂).

<h3>How we calculate mass from moles?</h3>

Mass of any substance can be calculated by using moles as:

n = W/M, where

W = required mass

M= molar mass

Given chemical reaction is:

3Ca(NO₃)₂ + 2Na₃PO₄ → 6NaNO₃ + Ca₃(PO₄)₂

From the stoichiometry it is clear that:

3 moles of Ca(NO₃)₂ = produce 1 mole of Ca₃(PO₄)₂

Given mass of Ca(NO₃)₂ = 96.1g

Mole of Ca(NO₃)₂ = 96.1g/164g/mol = 0.5859moles

So, 0.5859 moles of Ca(NO₃)₂ = produce 0.5859×1/3 = 0.0196 moles of Ca₃(PO₄)₂

Required mass of Ca₃(PO₄)₂ will be calculated by using moles as:

W = 0.0196mole × 310g/mole = 6.07 grams

Hence, 6.07 grams is the theoretical yield of calcium phosphate.

To know more about moles, visit the below link:

brainly.com/question/15373263

7 0

2 years ago

How did changing from a light drizzle to a downpour affect the river and the sediment un it

soldi70 [24.7K]

Answer:

The velocity of the river increased.

There was more erosion in the stream.

The type of sediment that moved changed.

Explanation:

6 0

3 years ago