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tatuchka [14]
3 years ago
5

A scientist measures the standard enthalpy change for the following reaction to be -17.2 kJ : Ca(OH)2(aq) 2 HCl(aq)CaCl2(s)

Chemistry
1 answer:
elixir [45]3 years ago
8 0

Answer: \Delta H^{0}=-173.72 kJ/mol

Explanation: <u>Enthalpy</u> <u>Change</u> is the amount of energy in a reaction - absorption or release - at a constant pressure. So, <u>Standard</u> <u>Enthalpy</u> <u>of</u> <u>Formation</u> is how much energy is necessary to form a substance.

The standard enthalpy of formation of HCl is calculated as:

\Delta ^{0}=\Sigma H_{products}-\Sigma H_{reactants}

Ca(OH)_{2}_{(aq)}+2HCl_{(aq)} → CaCl_{2}_{(s)}+2H_{2}O_{(l)}

Standard Enthalpy of formation for the other compounds are:

Calcium Hydroxide: \Delta H^{0}= -1002.82 kJ/mol

Calcium chloride: \Delta H^{0}= -795.8 kJ/mol

Water: \Delta H^{0}= -285.83 kJ/mol

Enthalpy is given per mol, which means we have to multiply by the mols in the balanced equation.

Calculating:

-17.2=[-795.8+2(285.85)]-[-1002.82+2\Delta H]

-17.2=-1367.46+1002.82-2\Delta H

2\Delta H=17.2-364.64

\Delta H=-173.72

So, the standard enthalpy of formation of HCl is -173.72 kJ/mol

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What is the concentration of H+ in 0.0025 M HClO4? What is the pH of the solution? What is the OH− concentration in the solution
alexandr402 [8]

Answer:

A. The concentration of H+ is 0.0025 M

B. The pH is 2.6

C. The concentration of OH- is 3.98x10^-12 M

Explanation:

We'll begin by writing the balanced

dissociation equation of HClO4. This is illustrated below:

HClO4 —> H+ + ClO4-

A. Determination of the concentration of H+ in 0.0025 M HClO4. This is illustrated below:

From the balanced equation above,

1 mole of HClO4 produced 1 mole of H+.

Therefore, 0.0025 M of HClO4 will also produce 0.0025 M of H+.

The concentration of H+ is 0.0025 M

B. Determination of the pH.

The pH of the solution can be obtained as follow:

The concentration of H+, [H+]

= 0.0025 M

pH =?

pH = - log [H+]

pH = - log 0.0025

pH = 2.6

C. Determination of the concentration of OH-

To obtain the concentration of OH-, we must first calculate the pOH of the solution. This is illustrated below:

pH + pOH = 14

pH = 2.6

pOH =?

pH + pOH = 14

2.6 + pOH = 14

Collect like terms

pOH = 14 - 2.6

pOH = 11.4

Now, we can calculate the concentration of the OH- as follow:

pOH = - Log [OH-]

pOH = 11.4

11.4 = - Log [OH-]

- 11.4 = log [OH-]

[OH-] = anti log (- 11.4)

[OH-] = 3.98x10^-12 M

8 0
3 years ago
2NaHCO3--&gt;Na2CO3+H2O+CO2
algol [13]
I’m not sure what kind of answer you’re looking for, but if you’re supposed to translate it into a sentence it would be two moles of sodium bicarbonate(baking soda) decompose unto one mole of sodium carbonate(soda ash) plus one mole of water and one mole of carbon monoxide gas
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Hemoglobin has a much greater affinity for carbon monoxide than oxygen. which principle explains why a hyperbaric chamber (conta
babunello [35]

Hemoglobin has a much greater affinity for carbon monoxide than oxygen. In a hyperbaric chamber (containing high levels of oxygen) can treat carbon monoxide poisoning, by displacing carbon monoxide from Hemoglobin competitively.

Hemoglobin has a much greater affinity for carbon monoxide than oxygen. This is because, a coordinate bond is formed with Carbon monoxide and Haem structure of the hemoglobin.

Carbon monoxide with Hemoglobin is called as Carboxy haemoglobin.

Presence of oxygen displaces the Carbon monoxide with Hemoglobin that is formed due to poisoning.

Hyperbaric chamber is a chamber which contains pure oxygen in a chamber. The atmospheric pressure is kept about three to four times than the normal, such that the replacement of Carbon monoxide from Haem can occur as fast as possible since this reduces the half life of the Carboxy haemoglobin.

It is advisable not to treat Carbon monoxide poisoning yourself.

Hyperbaric oxygen is used to treat the following conditions as well:

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Learn more about Carbon Monoxide here, brainly.com/question/11313918

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3 0
1 year ago
How does the amount of daylight affect the number of eggs laid by a chicken?
IrinaVladis [17]
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8 0
3 years ago
Give an example of how you could use different reference frames for the same motion.
RUDIKE [14]

Answer:

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Explanation:

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