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:
Baking Soda is NaHCO3 ---Sodium hydrogen Carbonate
Excessive use of Fertilizer can cause plants to develop shallow root systems,Decrease soil fertility and reduce Quality of Crops.
Answer:
polymerization
Explanation:
Student is explaining the process of formation of a polymer and the process is called polymerization.
Polymer is made up of joining repeating units. The repeating units are called monomers.
Properties of the polymer is determined by the structure of monomer molecule.
For example, consider a well-known polymer Teflon.is made by the polymerization of tetrafluoroethane.
Thus, the student is explaining polymerization.
<u>Given:</u>
Mass of solvent water = 4.50 kg
Freezing point of the solution = -11 C
Freezing point depression constant = 1.86 C/m
<u>To determine:</u>
Moles of methanol to be added
<u>Explanation:</u>
The freezing point depression ΔTf is related to the molality m through the constant kf, as follows:
ΔTf = kf*m
where ΔTf = Freezing point of pure solvent (water) - Freezing pt of solution
ΔTf = 0 C - (-11.0 C) = 11.0 C
m = molality = moles of methanol/kg of water = moles of methanol/4.50 kg
11.0 = 1.86 * moles of methanol/4.50
moles of methanol = 26.613 moles
Ans: Thus around 26.6 moles of methanol should be added to 4.50 kg of water.
Answer: There was a lower concentration of salt in the water than in the cells.
Explanation:
Osmosis is a process in which the solvent flow from a solution of low concentration to a solution of high concentration through a semi-permeable membrane.
When the red blood cells are put in water that contained salt and the red blood cells burst after some time.
This means the solvent has moved from outside to inside the cell and this is possible only when the concentration of solute is high inside the cell than outside. That means the solution has low concentration of solute as compared to the cell and was a hypotonic solution.