Answer:- 
Explanations:- The first reaction is combustion reaction as the hydrocarbon is burned in presence of oxygen to give carbon dioxide and water.
Second reaction is the synthesis reaction as in general a synthesis reaction looks like:

Third reaction is the decomposition reaction as it looks opposite of synthesis reaction.

In general, a single displacement reaction looks like:

Fourth reaction is single replacement reaction as bromine is replaced by chlorine.
So, the correct choice is the last reaction,
.
Answer:
The increasing order of conductivity is O< Ge< Mn.
Explanation:
Electrical conductivity is defined as the measure of the ability of a material to conduct electrical current through it. The conductivity depends on the atomic and molecular structure of the material.
Metals are good conductors because they have a structure with many electrons with weak bonds, and this allows their movement instead non-metals have between four and eight valence electrons, which lack this tendency.
The conductivity increases in the periodic table from top to bottom and from right to left.
oxygen is a nonmetal therefore it is a bad conductor.
Germanium is a metalloid whose conductivity is greater than a nonmetal and worst than a metal.
Manganese is a metal,in this case, it is a good conductor.
The answer I believe is 3.340kj.