White P4
Red P4
P2O3
H3PO3
White P4 + alkali → H3PO2
Red P4 + alkali → H4P2O6
No P-H bond
Complete the following reactions by writing the structure of the main products: 
Nature of compounds TeO₂ and TeH₂ is___________ and ______________respectively.
Consider the following sequence of reactions : 
Molar mass of the product formed (A) is ______ g mol\(^{-1}\).
The magnitude of heat exchanged by a system for the given cyclic process ABC (as shown in the figure) is (in SI units):

Hydrocarbons are organic compounds that are entirely made up of only two kinds of atoms – carbon and hydrogen. Typically, hydrocarbons are colourless gases that have very weak odours.
According to experimental evidences, SE (S = substitution; E = electrophilic) reactions are supposed to proceed via the following three steps: