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castortr0y [4]
3 years ago
6

What is the enthalpy of formation (?H?f) of NaHCO3(s) from its constituent elements.

Chemistry
2 answers:
vova2212 [387]3 years ago
7 0

Answer:

Enthalpy of formation = -947.68KJ/mol

Explanation:

Enthalpy of formation is the heat change when one mole of a substance is formed from its element in its standard states and in standard conditions of temperature and pressure. it may be positive or negative, if positive, it is an endothermic reaction where the heat content of the product is greater than that of the reactants, and if negative, it is exothermic reaction - where the heat content of the reactants is greater than the products. the enthalpy of formation is measured in KiloJoule/Moles (KJ/Mole).

From the value of the enthalpy of formation of NaHCO3, it shows that the reaction is exothermic, that is the formation of NaHCO3 from its constituents elements. As such, the heat content of the reactants is greater than the products.

The step by step explanation is shown in the attachment.

Shtirlitz [24]3 years ago
3 0

Answer:

-947.6 kJ/mol.

Explanation:

The constituent elements combined to result in NaHCO3(s)

NaHCO3(s) → (1/2).Na2CO3(s) + (1/2).CO2(g) + (1/2).H2O(g) : ΔHr = +64.6 kJ/mol

Enthalpy change of a reaction can be measured and given the symbol,  . It is equal to the difference in enthalpy between reactants and products

From this equation we deduct that water is produced as a vapour, hence the reaction is endotermic and ΔHr is positive.

Therefore, To find the enthalpy of formation of NaHCO3 from this equation, we use the general equation which relates the enthalpy change ΔHr of the reaction to the enthalpies ΔHf of formation for the reactants and products.

ΔHr = ∑ΔH(products) - ∑ΔH(reagents)

where the  

ΔH is equal to the change in the potential energy of enthalpy of the chemical bond.

In ideal test scenarios, these values should be supplied, as you will not be able to look them up. Here, I've supplied values here.

ΔHf : Na2CO3(s) = -1130.7, CO2(g) = -393.5, H2O(g) = -241.8 kJ/mol

Using these figures (you may wish to check them in Wikipedia or elsewhere), we get

+64.6 = [(1/2)*(-1130.7) + (1/2)*(-393.5) + (1/2)*(-241.8)] - ΔHf(NaHCO3)

With the result that the enthalpy of formation of NaHCO3 is obtained as -947.6 kJ/mol.

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Answer:

5.41 ×10⁻²²

Explanation:

We were told right from the question that both the Zinc ions and the Zinc oxide adopts a face-centered cubic arrangement.

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2 years ago
The volume of an irregular solid can be found from its displacement in a known volume of water.
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Answer:

The volume of an irregularly shaped solid can be determined from the volume of water it displaces. A graduated cylinder contains 19.9 mL of water. When a small piece of galena is added, it sinks and the volume increases to 24.5 mL

4 0
3 years ago
Gaseous ammonia chemically reacts with oxygen O2 gas to produce nitrogen monoxide gas and water vapor. Calculate the moles of am
mel-nik [20]

Answer:

1.7 moles of ammonia, NH₃.

Explanation:

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

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From the balanced equation above,

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Finally, we shall determine the number of mole of ammonia, NH₃, needed to produce 1.7 moles of nitrogen monoxide, NO. This can be obtained as follow:

From the balanced equation above,

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Therefore, 1.7 moles of NH₃ will also react to produce 1.7 moles of NO.

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DR is the correct answer

hope this helps
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What is the difference between a renewable and nonrenewable resource
ioda

Answer:

Answer in explanation

Explanation:

A renewable source of energy is an energy source that cannot be depleted. It is an energy source with constant abundance and hence it is always in abundance. What we are saying is that they are energy sources that cannot be used up. Although it might sometimes be that it is unavailable at some instances, this does not take away the fact that it is abundant and cannot be depleted, although the strength at different times may vary. Example of renewable energy sources include solar energy, wind energy, hydroelectric power source etc. These sources are never depleted and are in abundance.

Non renewable source of energy are those sources of energy that can be depleted. A good example of this can be seen in fossil fuels. Fossil fuels are usually burned to produce energy. They are used up in the process and it will require an additional amount of fossil fuel to be restocked for the energy to be continually supplied.

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