Answer:
c = 0.898 J/g.°C
Explanation:
1) Given data:
Mass of water = 23.0 g
Initial temperature = 25.4°C
Final temperature = 42.8° C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.18 J/g°C
ΔT = 42.8°C - 25.4°C
ΔT = 17.4°C
Q = 23.0 g × × 4.18 J/g°C × 17.4°C
Q = 1672.84 j
2) Given data:
Mass of metal = 120.7 g
Initial temperature = 90.5°C
Final temperature = 25.7 ° C
Heat released = 7020 J
Specific heat capacity of metal = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.7°C - 90.5°C
ΔT = -64.8°C
7020 J = 120.7 g × c × -64.8°C
7020 J = -7821.36 g.°C × c
c = 7020 J / -7821.36 g.°C
c = 0.898 J/g.°C
Negative sign shows heat is released.
The pH of the unknown solution is 3.07.
<u>Explanation:</u>
<u>1.Find the cell potential as a function of pH</u>
From the Nernst Equation:
Ecell=E∘cell−RT /zF × lnQ
where
R denotes the Universal Gas Constant
T denotes the temperature
z denotes the moles of electrons transferred per mole of hydrogen
F denotes the Faraday constant
Q denotes the reaction quotient
Substitute the values,
E∘cell=0 lnQ=2.303logQ
E0cell=−2.30/RT /zF × log Q
Solving the equation,
<u>2. Find the Q value</u>
Q=[H+]2prod pH₂, product/ [H+]2reactpH₂, reactant
Q=[H+]^2×1/1×1=[H+]2
Taking the log
logQ= log[H+]^2=2log[H+]=-2pH
From the formula,
Ecell=−2.303RT /zF× logQ
E cell= 2.303 × 8.314 CK mol (inverse) × 298.15
K × 2pH /2×96 485 C⋅mol
( inverse)
E cell= 0.0592 V × pH
<u>3. Finding the pH value</u>
E cell= 0.0592 V × pH
pH = E cell/ 0.0592 V= 0.182V/ 0.0592V
pH=3.07
The pH of the unknown solution is 3.07.
Answer is: <span>- delta G.
</span>The change in Gibbs free energy (ΔG), at constant temperature and pressure, is: <span>ΔG=ΔH−TΔS.
</span>ΔH<span> is the change in enthalpy.
</span>ΔS is change in entropy.
T is temperature of the system.
When ΔG is negative, a reaction (<span>occurs without the addition of external energy)</span><span> will be spontaneous (</span>exergonic).
Answer:
Newton's third law of motion states that every action, there is an equal and opposite reaction force and that forces come in pairs
Among the elements Barium has the lowest Ionization Energy.
<h3>What is Ionization Process ?</h3>
The process by which any neutral atom gets converted into electrically charged by gaining or losing electron is called Ionization Process.
K is an alkali metal it has to lose one electron to attain stable electronic configuration of an inert gas
For removing second electron , a stable configuration has to be broken and so will require high amount of energy.
Ca and Ba are alkaline earth metals.
They both have to lose 2 electrons to attain stable electronic configuration of noble gas.
They have low Iow Ionization Energy as compared to K.
Ca has higher Ionization Energy as compared to Ba because when we move down the periodic table , The ionization energy decreases.
Hence , Among the elements Barium has the lowest Ionization Energy.
To know more about Ionization Process
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