The standard entropy of Pb(s) at 298.15 K is 64.80 J K–1 mol–1. Assume that the heat capacity of Pb(s) is given by: CP,m(Pb, s) J K−1mol−1 = 22.13 + 0.01172 T K + 1.00 x 10−5 T 2 K2 The melting point is 327.4 ℃ and the heat of fusion is 4770 J mol-1. Assume that the heat capacity of Pb(l) is given by: CP,m(Pb, l) J K−1mol−1 = 32.51 − 0.00301 T K Calculate the standard entropy of Pb(l) at 500 ℃
Answers
Answer:
Explanation:
Hello,
In this case, for the calculation of the standard entropy of liquid lead at 500 °C (773.15 K), starting by solid lead 298.15 K we need to consider three processes:
1. Heating of solid lead at 298.15 K to 600.55 K (melting point).
2. Melting of solid lead to liquid lead.
3. Heating of liquid lead at 600.55 K (melting point) to 773.15 K.
Which can be written in terms of entropy by:
Whereas each entropy is computed as follows:
Therefore, the standard entropy of liquid lead at 500 °C turns out:
Best regards.
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Calculate the molar solubility of Cd(OH)2 when buffered at a pH = 12.30. The Ksp for Cd(OH)2 is 2.5 x 10-14. Calculate the molar solubility of Cd(OH)2 when buffered at a pH = 12.30. The Ksp for Cd(OH)2 is a.2.5 x 10-14 M. b. 8.5 x 10-6 M c. 6.3 x 10-11 M d. 1.3 x 10-12 M e. 5.0 x 10-2 M f. 1.8 x 10-5 M
the specific heat of the resulting Nacl solutions is 4.06j/gc
calculate the heat of neutralisation of hcl and naoh in kj/mol nacl products
Answers
Answer:
62.12kJ/mol
Explanation:
The neutralization reaction of HCl and NaOH is:
HCl + NaOH → NaCl + H₂O + HEAT
You can find the released heat of the reaction and heat of neutralization (Released heat per mole of reaction) using the formula:
Q = C×m×ΔT
Where Q is heat, C specific heat of the solution (4.06J/gºC), m its mass and ΔT change in temperature (27.5ºC-20.0ºC = 7.5ºC).
The mass of the solution can be finded with the volume of the solution (50.0mL of HCl solution + 50.0mL of NaOH solution = 100.0mL) and its density (1.02g/mL), thus:
100.0mL × (1.02g / mL) = 102g of solution.
Replacing, heat produced in the reaction was:
Q = C×m×ΔT
Q = 4.06J/gºC×102g×7.5ºC
Q = 3106J = 3.106kJ of heat are released.
There are 50.0mL ×1M = 50.0mmoles = 0.0500 moles of HCl and NaOH that are reacting releasing 3.106kJ of heat. That means heat of neutralization is:
3.106kJ / 0.0500mol of reaction =
62.12kJ/mol is heat of neutralization
Answers
Answer:
The final pressure is 0.788 atm (option b).
Explanation:
Boyle's law says that the volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure. That is: if the pressure increases, the volume decreases, while if the pressure decreases, the volume increases. This is expressed mathematically as the product of pressure times volume equal to a constant value:
P*V=k
Assuming a certain volume of gas V1 that is at a pressure P1 at the beginning of the experiment, by varying the volume of gas to a new value V2, then the pressure will change to P2, and it will be fulfilled:
P1*V1=P2*V2
In this case:
- P1= 2.14 atm
- V1= 3 L
- P2= ?
- V2= 8.15 L
Replacing:
2.14 atm*3 L= P2* 8.15 L
Solving:
0.788 atm= P2
The final pressure is 0.788 atm (option b).
Answers
The statement about reaction A and reaction B are true is: A. Reaction B is likely to occur at a faster rate than reaction A.
An activation energy can be defined as the minimum quantity of energy that must be provided for reacting chemical elements, so as to undergo a chemical reaction. Thus, the activation energy of a chemical reaction must first of all be reached by its combining chemical elements (reactants) before it can start or begin.
As a general rule, the lower the activation energy of a chemical reaction, the faster is the rate of a chemical reaction and vice-versa. This ultimately implies that, the activation energy of a chemical reaction should be lowered, in order for it to occur fast (quickly) enough over a short period of time.
In conclusion, reaction B is likely to occur at a faster rate than reaction A because of its low activation energy.
Read more: brainly.com/question/537100
Answer:
The correct answer is:
Reaction B is more likely to occur at all than reaction A.
Explanation:
The activation energy in chemistry is the smallest amount of energy required to cause chemical or nuclear reaction in the reactants in chemical or nuclear systems. The activation energy is denoted by , and it is measured in Joules (J), KiloJoules (KJ) or Kilocalories per mole (Kcal/mol)
The activation energy can be thought of simply as the minimum amount of energy required to overcome a barrier that prevents a reaction from occurring, hence, from our question, if Reaction A has a high activation energy, it means that the barrier to be overcome before a reaction will occur is large, meaning that the reaction system is more stable and the reaction is less likely to occur than Reaction B which has a low activation energy, meaning that just a relatively small amount of energy, when applied to the reaction system, will initiate a reaction, making it more likely to occur than reaction A.
You should also note that catalysts are substances that are capable of reducing the activation energy of a system, but remains unchanged at the end of the system.
Answers
Answer: 3. basic
Explanation:
pH is the measure of acidity or alkalinity of a solution.
pH is measured by taking negative logarithm of hydrogen ions concentration.
Electrolyte is a solution which contains ions dissolved in water and hence is a good conductor of electricity.
A basic solution has more concentration of as compared to
.
An neutral solution has equal concentration of as that of
.
An acidic solution has more concentration of as compared to
.
Answers
Answer:
Speed of wave = 1500 m/s
Explanation:
Given data:
Frequency of wave = 10 Hz
Wavelength of wave = 150 m
Speed of wave = ?
Solution:
Formula:
Speed of wave = Frequency × Wavelength
Now we will put the values in formula.
Speed of wave = 10 Hz × 150 m
Speed of wave = 1500 m/s
Hz = s⁻¹
Answers
Answer: Option (2) is the correct answer.
Explanation:
Atomic number of oxygen atom is 8 and its electronic distribution is 2, 6. So, it contains only 2 orbitals which are closer to the nucleus of the atom.
As a result, the valence electrons are pulled closer by the nucleus of oxygen atom due to which there occurs a decrease in atomic size of the atom.
Whereas atomic number of sulfur is 16 and its electronic distribution is 2, 8, 6. As there are more number of orbitals present in a sulfur atom so, the valence electrons are away from the nucleus of the atom.
Hence, there is less force of attraction between nucleus of sulfur atom and its valence electrons due to which size of sulfur atom is larger than the size of oxygen atom.
Thus, we can conclude that the oxygen atom is smaller than the sulfur atom because the outer orbitals of oxygen are located closer to the nucleus than those of sulfur.
Final answer:
The oxygen atom is smaller than the sulfur atom because the outer orbitals of oxygen are located closer to the nucleus than those of sulfur.
Explanation:
The correct option is (2) the outer orbitals of oxygen are located closer to the nucleus than those of sulfur.
To understand why the oxygen atom is smaller than the sulfur atom, we need to consider their electron configurations. Oxygen has 8 electrons and sulfur has 16 electrons. Oxygen's electron configuration is 1s²2s²2p⁴, while sulfur's electron configuration is 1s²2s²2p⁶3s²3p⁴.
The outer orbitals of an atom, which are the valence orbitals, are the ones involved in bonding. The electrons in these orbitals determine the size of the atom. In the case of oxygen and sulfur, the outer orbitals of oxygen (2p orbitals) are closer to the nucleus compared to sulfur's outer orbitals (3p orbitals). As a result, the oxygen atom is smaller than the sulfur atom.
Learn more about Atomic structure here:
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