Open system ( exchanges energy and matter with the surroundings)
Closed system ( exchanges only energy with the surroundings)
Isolated system ( does not exchange energy or matter)
Adiabatic system ( does not allow any heat to be transferred into or out of the system)
Answer:
The first element is always named first, using entire element name.
Second element is named using its root and adding the suffix -ide.
Prefixes are used to indicate the number of atoms of each element that are present in the compound.
Explanation:
The term Big Bang defines that the Universe has expanded from the ancient hot and thick primary situation at some fixed time in the past.
Big Bang theory refers to the origin of the Universe. In the beginning, universe is very heavy and small hot ball of matter. It was a point no bigger than the head of a pin when all the things squished with each other and universe is expanded with huge explosion of energy. Due to expansion, it is cooled and results in the formation of Stars and galaxies. After sometime, atoms formed like helium and hydrogen.
Thus, statement (1), (3) and (4) is correct whereas statement (2) and (5) is incorrect.
Answer: Option (3) is the correct answer.
Explanation:
A reaction due to which there occurs change in chemical composition of reactants is known as a chemical reaction.
For example, evolution of heat when two substances combine together shows a chemical reaction has taken place between the substances.
Whereas a reaction which does not bring any changes in chemical composition of the reactants is known as a physical reaction.
For example, boiling point, melting point, mass, volume etc are all physical properties.
Thus, we can conclude that out of the given options a substance melts when sitting in the Sun, is not an indication of a chemical reaction.
Answer: a) Anode: 
Cathode: 
b) Anode : Cr
Cathode : Au
c) 
d) 
Explanation: -
a) The element Cr with negative reduction potential will lose electrons undergo oxidation and thus act as anode.The element Au with positive reduction potential will gain electrons undergo reduction and thus acts as cathode.
At cathode:
At anode:
b) At cathode which is a positive terminal, reduction occurs which is gain of electrons.
At anode which is a negative terminal, oxidation occurs which is loss of electrons.
Gold acts as cathode ad Chromium acts as anode.
c) Overall balanced equation:
At cathode: (1)
At anode: (2)
Adding (1) and (2)
d)
= -0.74 V
= 1.40 V
Using Nernst equation :
![E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Au^{3+}]}{[Cr^{3+}]^}](https://tex.z-dn.net/?f=E_%7Bcell%7D%3DE%5Eo_%7Bcell%7D-%5Cfrac%7B0.0592%7D%7Bn%7D%5Clog%20%5Cfrac%7B%5BAu%5E%7B3%2B%7D%5D%7D%7B%5BCr%5E%7B3%2B%7D%5D%5E%7D)
where,
n = number of electrons in oxidation-reduction reaction = 3
= standard electrode potential = 2.14 V
![E_{cell}=2.14-\frac{0.0592}{3}\log \frac{[1.0}{[1.0]}](https://tex.z-dn.net/?f=E_%7Bcell%7D%3D2.14-%5Cfrac%7B0.0592%7D%7B3%7D%5Clog%20%5Cfrac%7B%5B1.0%7D%7B%5B1.0%5D%7D)
Thus the standard potential for an electrochemical cell with the cell reaction is 2.14 V.
