Answer :
The correct answer is due to incorrect position of thermometer .
Distillation is process of separating two volatile liquids on the basis of their boiling points .In involves the following set up ( shown in image )
Since the Boiling point is found is 116-117 C which is near to 124 C , also the purity was checked and thermometer was calibrated .
So the only error could be possible is position of thermometer .
The position of bulb of thermometer is very important to get an accurate reading of boiling point .The vapor so formed should touch the side walls of bulb as soon as they are formed .
May be the bulb of thermometer was kept far from the vapors formed by liquid so, s<u>ome of the vapor before reaching to bulb start condensing and their Temperature decreases </u>.
Hence , the temperature shown by thermometer was decrease than actual boiling point due to incorrect position of thermometer.
Answer is: a product of a fermentation reaction is ethanol (C₂H₅OH).
Fermentation is a metabolic process in which ethanol is produced from sugar in the absence of oxygen (anaerobic digestion)<span>.
</span>Fermentation <span>occurs in </span>yeast, bacteria and in oxygen-starved muscle cells.
Fermentation is a way of extracting energy from molecules and it is <span>the oldest metabolic pathway.</span>
Answer: 1. C. polar covalent: electrons shared between silicon and sulfur but attracted more to the sulfur
2. B) 
3. B) Fluorine
Explanation:
1. A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.
Electronegativity difference = electronegativity of sulphur- electronegativity of silicon = 2.5 -1.8 = 0.7
Thus as electronegativity difference is less than 1.7 , the cond is polar covalent and as electronegativity of sulphur is more , the electrons will be more towards sulphur.
2. A molecular compound is usually composed of two or more nonmetal elements. Example:
Ionic compound is formed by the transfer of electrons from metals to non metals. Example: 
, 
and 
3. For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here K is having an oxidation state of +1 and as the compound formed is KZ, the oxidation state of non metallic element Z should be -1. Thus the element Z is flourine which exists as diatomic gas 
