Which of the following reactions are exothermic?

 

$$\begin{gathered} 1) C + O2 → CO2 \\ 2) 2Mg + O2 → 2MgO \\ 3) CuSO4 + 5H2O → CuSO4.5H2O \\ 4) All the above \end{gathered}$$

Silver chloride is a chemical compound with the chemical formula AgCl is also called as Horn Silver. It is also called as cerargyrite. It is a gray, very heavy halide mineral and an ore of silver.

Chemical weathering is the process of altering rocks chemically when they are broken down. It includes hydrolysis, oxidation, acid rain, etc...

Ethylene Glycol is an antifreeze is an additive which lowers the freezing point of a water-based liquid and increases its boiling point. 

Dry distillation of calcium acetate and calcium formate leads to the formation of aldehydes and ketones.

Simple covalent compounds are generally named by using prefixes metal name + nonmetal name + suffix –ide to indicate how many atoms of each element are shown in the formula. Also, the ending of the last (most negative) element is changed to -ide. The prefixes used are mono-, di-, tri-, tetra-, penta-, hexa-, and so forth.

Convection is the mode of heat transfer which involves bulk motion of a fluid to transfer heat. Energy transfer by convection is primarily restricted to fluids. Fluids can be both liquids and gases.

The principal quantum number is the property of an electron which determines the energy of electron and the distance of electron from the nucleus of an atom.