Question

For questions 18-21, . In each space, classify the reaction type.

18. ____________________ 2LiBr + Pb(NO3) - PbBr2 + 2LiNO3
19. ____________________ Fe + 2HCl - FeCl2 + H2
20. ____________________ CaO + H2O - Ca(OH)2
21. ____________________ NiCl2 - Ni + Cl2

Answer 1

18. Double Displacement Reaction

19. Single Displacement Reaction

20. Synthesis Reaction

21. Decomposition Reaction

Step-by-step explanation:

Double Displacement formula:

AB + CD --> AD + CB

Single Displacement formula:

A + BC --> AC + B

Synthesis formula:

A + B --> AB

Decomposition formula:

AB --> A + B

Answer 2

`2LiBr+Pb(NO_3) = PbBr_2+ 2LiNO_3` is a double displacement reaction

• 
  `Fe+2HCl  = FeCl_2+2H_2` is a redox reaction

• 
  `CaO+H_2 O = Ca(OH)_ 2`is a combination reaction

• 
  `NiCl_2 = Ni+Cl_2` is a decomposition reaction

Step-by-step explanation:

`2LiBr+PbNO_3 = PbBr_2+2LiNO_3`

It is of the form
`AX+BY = AY+BX`

`Fe+2HCl = FeCl_2+H_2`

Both oxidation and reduction occur in this reaction. Fe gets oxidized and H gets reduced.

`Fe = Fe^(2+)+2e^-`

`2H^++2e^- = H_2`

`CaO+H_2 O = Ca(OH)_2`

It is an exothermic combination reaction. Calcium reacts with water to produce calcium hydroxide and heat is released in this process.

• 
  `NiCl_2 = Ni+Cl_2`

It is a decomposition reaction where nickel chloride decomposes to nickel and chlorine.