Answer:
A. ΔG° = 132.5 kJ
B. ΔG° = 13.69 kJ
C. ΔG° = -58.59 kJ
Explanation:
Let's consider the following reaction.
CaCO₃(s) → CaO(s) + CO₂(g)
We can calculate the standard enthalpy of the reaction (ΔH°) using the following expression.
ΔH° = ∑np . ΔH°f(p) - ∑nr . ΔH°f(r)
where,
n: moles
ΔH°f: standard enthalpy of formation
ΔH° = 1 mol × ΔH°f(CaO(s)) + 1 mol × ΔH°f(CO₂(g)) - 1 mol × ΔH°f(CaCO₃(s))
ΔH° = 1 mol × (-635.1 kJ/mol) + 1 mol × (-393.5 kJ/mol) - 1 mol × (-1206.9 kJ/mol)
ΔH° = 178.3 kJ
We can calculate the standard entropy of the reaction (ΔS°) using the following expression.
ΔS° = ∑np . S°p - ∑nr . S°r
where,
S: standard entropy
ΔS° = 1 mol × S°(CaO(s)) + 1 mol × S°(CO₂(g)) - 1 mol × S°(CaCO₃(s))
ΔS° = 1 mol × (39.75 J/K.mol) + 1 mol × (213.74 J/K.mol) - 1 mol × (92.9 J/K.mol)
ΔS° = 160.6 J/K. = 0.1606 kJ/K.
We can calculate the standard Gibbs free energy of the reaction (ΔG°) using the following expression.
ΔG° = ΔH° - T.ΔS° 
where,
T: absolute temperature
<h3>A. 285 K</h3>
ΔG° = ΔH° - T.ΔS°
ΔG° = 178.3 kJ - 285K × 0.1606 kJ/K = 132.5 kJ
<h3>B. 1025 K</h3>
ΔG° = ΔH° - T.ΔS°
ΔG° = 178.3 kJ - 1025K × 0.1606 kJ/K = 13.69 kJ
<h3>C. 1475 K</h3>
ΔG° = ΔH° - T.ΔS°
ΔG° = 178.3 kJ - 1475K × 0.1606 kJ/K = -58.59 kJ
 
        
             
        
        
        
Answer:
N2O2(g) +O2(g) ===> 2NO2(g)
Explanation:
For a nonelementary reaction, the reaction equation is described as the sum of all the steps involved. All these steps constitute the reaction mechanism. Each step in the mechanism is an elementary reaction. The rate law of the overall reaction involves the rate determining step (slowest step) in the reaction sequence.
Now look at the overall reaction 2NO(g) + O2(g) ---------> 2NO2(g)
The two steps in the mechanism are
2NO(g) --------->N2O2(g) (fast)
N2O2(g) +O2(g) -------> 2NO2(g) (slow)
Summing all the steps and cancelling out the intermediate N2O2(g), we obtain the reaction equation;
2NO(g) + O2(g) ---------> 2NO2(g)
Hence the answer.
 
        
             
        
        
        
Answer:
3 × 10^8 m/s
Explanation:
The wavelength, can be calculated by using the following formula;
λ = v/f
Where;
λ = wavelength (m)
v = velocity/speed of light (m/s)
f = frequency (Hz)
According to the provided information in this question, λ = 600nm i.e. 600 × 10^-9m, f = 5.00 x 10^14 Hz
Hence, using λ = v/f
v = λ × f
v = 600 × 10^-9 × 5.00 x 10^14
v = 6 × 10^-7 × 5.00 x 10^14
v = 30 × 10^(-7 + 14)
v = 30 × 10^ (7)
v = 3 × 10^8 m/s
 
        
             
        
        
        
Answer:  13.9 g of  will be produced from the given mass of oxygen
 will be produced from the given mass of oxygen
Explanation:
To calculate the moles :
 
    

The balanced chemical reaction is:
 
 
According to stoichiometry :
7 moles of  produce =  6 moles of
 produce =  6 moles of 
Thus 0.900 moles of  will produce =
 will produce = of
  of 
Mass of 
Thus 13.9 g of  will be produced from the given mass of oxygen
 will be produced from the given mass of oxygen
 
        
             
        
        
        
Answer:
D is correct 
Explanation:
because 
we know that 
density of lead is 11.36 g/cm3
and 
density of tin is 7.31 g/cm3
so..
density of alloy by mixing 50/50
=(11.36+7.31)/2 g/cm3
=18.67/2 g/cm3
=9.33 g/cm3