Identify the missing coefficient in the balanced equation and classify the type of reaction.
casn2 + 6h20 _ca(oh)2 + 2nh3
4: single displacement
3. single displacement
4: double displacement
3; double displacement

3; Double Displacement

Explanation:

Balancing is making the number of atoms of each element same on both the sides  (reactant and product side).

To find the number of atoms of each element we multiply coefficient and the subscript  

For example contains  

5 × 1 = 5 ,Ca atoms and

5 × 2 = 10, Cl atoms  

If there is a bracket in the chemical formula  

For example we multiply coefficient × subscript × number outside the bracket to find the number of atoms  

(Please note: 3 is the coefficient, and if there is no number given then 1 will be the coefficient )

So

3 × 3 = 9 , Ca atoms  

3 × 1 × 2 = 6, P atoms  

3 × 4 × 2 = 24, O atoms are present

Let us balance the equation  given

(UNBALANCED)

Reactant side           Number of atoms or groups                   Product side

                                       of each element    

3                                                 Ca                                                           1

2                                                  N                                                            2

12                                                H                                                            8

6                                                  O                                                            2

Multiplying on the right side by 3, we will have

Reactant side           Number of atoms or groups                   Product side

                                       of each element    

3                                                 Ca                                                           3

2                                                  N                                                            2

12                                                H                                                            12

6                                                  O                                                            6

Balanced

Option (a) is the correct answer.

Explanation:

According to collision theory, more is the number of collisions between the particles of reactants or a substance then more will be the rate of reaction.

Therefore, when we heat the solution then it will take time to heat up and thus, molecules will gain kinetic energy after a few minutes. As a result, collisions will start to occur and eventually rate of reaction will increase.

Whereas when we stir the solution while heating then immediately a disturbance is caused due to which atoms start to move and thus they gain kinetic energy. Therefore, rate of reaction will increase much faster due to stirring while heating.

On the other hand, when solute is dissolved into the solution and if no disturbance is caused then the reaction will be slow in nature as molecules are not colliding rapidly.

Hence, we can conclude that ranks who would fully dissolve the solute, from first to last are as follows.

                        Larry → Jessica → Hunter