Answer : The correct option is, +91 kJ/mole
Solution :
The balanced cell reaction will be,
Here copper (Cu) undergoes oxidation by loss of electrons, thus act as anode. Lead (Pb) undergoes reduction by gain of electrons and thus act as cathode.
First we have to calculate the standard electrode potential of the cell.
![E^0_{[Pb^{2+}/Pb]}=-0.13V](https://tex.z-dn.net/?f=E%5E0_%7B%5BPb%5E%7B2%2B%7D%2FPb%5D%7D%3D-0.13V)
![E^0_{[Cu^{2+}/Cu]}=+0.34V](https://tex.z-dn.net/?f=E%5E0_%7B%5BCu%5E%7B2%2B%7D%2FCu%5D%7D%3D%2B0.34V)
![E^0_{cell}=E^0_{[Pb^{2+}/Pb]}-E^0_{[Cu^{2+}/Cu]}](https://tex.z-dn.net/?f=E%5E0_%7Bcell%7D%3DE%5E0_%7B%5BPb%5E%7B2%2B%7D%2FPb%5D%7D-E%5E0_%7B%5BCu%5E%7B2%2B%7D%2FCu%5D%7D)
Now we have to calculate the standard Gibbs free energy.
Formula used :
where,
= standard Gibbs free energy = ?
n = number of electrons = 2
F = Faraday constant = 96500 C/mole
= standard e.m.f of cell = -0.47 V
Now put all the given values in this formula, we get the Gibbs free energy.
Therefore, the standard Gibbs free energy is +91 kJ/mole
The correct answer is 9.7 grams because mg are 1,000 difference to grams.
Answer:
The conservation of energy principle states that energy can neither be destroyed nor created. Instead, energy just transforms from one form into another. So what exactly is energy transformation? Well, as you might guess, energy transformation is defined as the process of changing energy from one form to another. There are so many different kinds of energy that can transform from one form to another. There is energy from chemical reactions called chemical energy, energy from thermal processes called heat energy, and energy from charged particles called electrical energy. The processes of fission, which is splitting atoms, and fusion, which is combining atoms, give us another type of energy called nuclear energy. And finally, the energy of motion, kinetic energy, and the energy associated with position, potential energy, are collectively called mechanical energy. That sounds like quite a lot, doesn't it? Well it is, but don't worry, it's actually all pretty easy to remember. Next, we'll explore all of these kinds of possible transformations in more detail. Different Types of Energy Transformations Chemical energy is the energy stored within a substance through the bonds of chemical compounds. The energy stored in these chemical bonds can be released and transformed during any type of chemical reaction. Think of when you're hungry. When you eat a piece of bread to satisfy this hunger, your body breaks down the chemical bonds of the bread and uses it to supply energy to your body. In this process, the chemical energy is transformed into mechanical energy, which you use to move, and which we'll cover in more detail in a moment. It also transforms it into thermal energy, which is created through the metabolic processes in your body to generate heat. Most of the time, chemical energy is released in the form of heat, and this transformation from chemical energy to heat, or thermal energy, is called an exothermic reaction. Next, there are two main types of mechanical energy: kinetic energy and potential energy. Kinetic energy is the energy associated with the motion of an object. Therefore, any object that moves has kinetic energy. Likewise, there are two types of potential energy: gravitational potential energy and elastic potential energy. Gravitational potential energy is associated with the energy stored by an object because of its location above the ground. Elastic potential energy is the energy stored by any object that can stretch or compress. Potential energy can be converted to kinetic energy and vice versa. For example, when you do a death-defying bungee jump off of a bridge, you are executing a variety of energy transformations. First, as you prepare to jump, you have gravitational potential energy - the bungee cord is slack so there is no elastic potential energy. Once you jump, you convert this gravitational potential energy into kinetic energy as you fall down. At the same time, the bungee cord begins to stretch out. As the cord stretches, it begins to store elastic potential energy. You stop at the very bottom when the cord is fully stretched out, so at this point, you have elastic potential energy. The cord then whips you back up, thereby converting the stored elastic potential energy into kinetic energy and gravitational potential energy. The process then repeats
Explanation:
here u go :P
Answer:
1.327 g Ag₂CrO₄
Explanation:
The reaction that takes place is:
- 2AgNO₃(aq) + K₂CrO₄(aq) → Ag₂CrO₄(s) + 2KNO₃(aq)
First we need to <em>identify the limiting reactant</em>:
We have:
- 0.20 M * 50.0 mL = 10 mmol of AgNO₃
- 0.10 M * 40.0 mL = 4 mmol of K₂CrO₄
If 4 mmol of K₂CrO₄ were to react completely, it would require (4*2) 8 mmol of AgNO₃. There's more than 8 mmol of AgNO₃ so AgNO₃ is the excess reactant. <em><u>That makes K₂CrO₄ the limiting reactant</u></em>.
Now we <u>calculate the mass of Ag₂CrO₄ formed</u>, using the <em>limiting reactant</em>:
- 4 mmol K₂CrO₄ *
= 1326.92 mg Ag₂CrO₄
- 1326.92 mg / 1000 = 1.327 g Ag₂CrO₄
