Answer:
Maintaining a high starting-material concentration can render this reaction favorable.
Explanation:
A reaction is <em>favorable</em> when <em>ΔG < 0</em> (<em>exergonic</em>). ΔG depends on the temperature and on the reaction of reactants and products as established in the following expression:
ΔG = ΔG° + R.T.lnQ
where,
ΔG° is the standard Gibbs free energy
R is the ideal gas constant
T is the absolute temperature
Q is the reaction quotient
To make ΔG < 0 when ΔG° > 0 we need to make the term R.T.lnQ < 0. Since T is always positive we need lnQ to be negative, what happens when Q < 1. Q < 1 implies the concentration of reactants being greater than the concentration of products, that is, maintaining a high starting-material concentration will make Q < 1.
Let's assume that the gas has ideal gas behavior.
Then we can use ideal gas equation,
PV = nRT
Where, <span>
P = Pressure of the gas (Pa)
V = volume of the gas (m³)
n = number of moles (mol)
R = Universal gas constant (8.314 J mol</span>⁻¹ K⁻¹)<span>
T = temperature in Kelvin (K)
<span>
The given data for the </span></span>gas is,<span>
P = 2.8 atm = 283710 Pa
V = 98 L = 98 x 10</span>⁻³ m³<span>
T = 292 K
R = 8.314 J mol</span>⁻¹ K⁻¹<span>
n = ?
By applying the formula,
283710 Pa x </span>98 x 10⁻³ m³ = n x 8.314 J mol⁻¹ K⁻¹ x 292 K
<span> n = 11.45 mol
Hence, moles of gas is </span>11.45 mol.
Answer:
Chemicals A and B form an endothermic reaction, and chemicals C and D form an exothermic reaction.
Explanation:
The reaction that produced chemical C is an endothermic reaction whereas, the reaction between C and D is an exothermic one.
An exothermic change is one in which heat is liberated to the surroundings. So the surrounding becomes hotter at the end of the reaction.
An endothermic reaction is a change in which heat is absorbed from the surrounding and hence the surrounding colder at the end of the change.
- We can see that the first reaction is endothermic.
- The second reaction is exothermic.
Density is equal to the ratio of mass to the volume.
The mathematical expression is given as:
Density of silver metal bar=
Convert 
into g/L
= 0.001 L
Thus, density = 
= 
Volume = 0.5 L
Put the values,
=
Now, convert gram into kg
1 g = 0.001 kg
Therefore, mass in kg= 
= 5.25 kg
Thus, mass of silver metal bar in kg=5.25 kg
