Sodium, a very reactive metal which reacts with chlorine gas and produces sodium chloride, the neutral salt. Sodium is oxidized to sodium cation (Na+) and chlorine gas is reduced to chloride anions (Cl-).
We know sodium is a very active metal and chlorine is also a very reactive non-metal. Usually, metals like to eliminate electrons and non-metals such as halogens like to accept electrons.
Sodium readily eliminate its last shell electrons become Na+ cation and chlorine accepts that electron to form Cl- anion.
Na + Cl2 → 2NaCl
Two moles of chlorine gas reacts with one mole of sodium to produce two moles of sodium chloride.
It is easy to balance this reaction by inspection method than redox method. Redox method will take much time. But it is useful in balancing large redox equations.
This is a so easy redox reaction to balance and if you are beginner to balancing equations, this is also an good example to start your redox reaction balancing.
Sodium is oxidized from 0 oxidation state and to +1 oxidation state. Chlorine is reduced to -1 oxidation state from 0 oxidation state. Write oxidation numbers if each atom close to the atoms.
Check the number of atoms of oxidized and reduced in the reaction (left and right side) and balance them if they are not balance, as the next step. In left side, there are two chlorine atoms. To balance them, make two sodium chloride in the right side. Then there are two sodium atoms in the right side of the reaction, but only one in the left side. Therefore, make two sodium atoms in the left.
Next, find oxidation number differences of oxidized atoms (sodium to sodium ion) and reduced atoms (chlorine to chloride). Oxidation number difference of sodium is two and for chlorine it is two. So they are same and cancel out each other.
The solid reactant, sodium reacts with green-yellow gaseous chlorine and produce solid sodium chloride which is a white crystalline solid.
This reaction occurs in a rapid rate because both reactants are very reactive. Sodium is a group 1 metal which likes to remove its outer electrons and chlorine desired to take electrons from outside.
Reaction of sodium and chlorine is an exothermic one (heat is released from the reaction). Enthalpy of the reaction is taken as enthalpy of formation of two moles sodium chloride.
Standard enthalpy of reaction = -411.12 kJ
Entropy of the reaction (2980C) = 72.10 J/(K mol)
Let's do a simple calculation.
You are going to mix 4 mol of sodium and 2 mol of chlorine gas. How much energy is released from the reaction? Standard enthalpy of formation of sodium chloride = -411.120 kJ/mol
Definition of Standard enthalpy of formation of sodium chloride: When 1 mol of sodium chloride is formed, 411.120 kJ is released to the outside. If 2 mol of sodium chloride is formed, 411.120 * 2 kJ is released to the outside.
Now you know, released heat depends on the formed sodium chloride amount. Now you now we have to find out how much sodium chloride is produced in this question.
According to the stoichiometry, to react with 1 mol of chlorine gas, 2 mol of sodium is required. Because of this, to react with 2 mol of chlorine gas, 4 mol of sodium is required and there is 4 mol at the beginning of the reaction.
If you mix considerable amount of chlorine gas and sodium, you can see the reaction is being occurred beacause reaction beaker will be red colour due to emission of large heat. If amount of reactants is low, perform qualitative analysis testings for sodium ion and chloride ion.
Questions
When sodium reacts with clorine gas, sodium chloride (NaCl) is given as the product. Yes. This is a composition reaction because two compounds combine together and produce one compound as product.
First thing is, in which phase sodium chloride want? Solid or aqueous or liquid NaCl? You have to plan your method according to the physical state of sodium chloride.
Reaction of sodium and chlorine is the direct way to prepare sodium chloride if you need solid NaCl. But, this reaction is too dangerous because it emitts large amount of energy and chlorine is a deathly toxic gas.
In the second method, you can prepare sodium chloride in aqueous state. So you need to remove water by a separation method, if you need solid sodium chloride. If you need aqueous sodium chloride, this is the best way to do.
Yes. Potassium reacts with chlorine and produce potassium chloride.
2K + Cl2 → 2KCl
Sodium + Chlorine gas → Sodium chloride
Lithium reacts with chlorine gas as sodium does. So equation is very similar to sodium and chlorine gas reaction.
2Li + Cl2 → 2LiCl
Yes. reaction happens.
Na + Cl2 → NaCl , this is not the balaced equation. This equation denotes only reactants and products.
Chlorine (Cl2) is very toxic and should be worked very carefully to avoid any injuries to people?
It is a combining reaction. Two reactants combine together to produce one product. Sodium and chlorine are the two reactants and sodium chloride is the only product.
Solid sodium metal+ Chlorine gas → Solid sodium chloride