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Multiple choice chemistry polymer polymers of commercial importance some commercially important polymers condensation polymers

Teflon (tetrafluoroethylene) is a black material used in non-stick pans for frying chips and vegetables. The oil or butter does not stick at all. In the process of manufacture, one of the technical problems is:

  1. to make teflon stick to the metal of the pan

  2. to make teflon that is non-sticky

  3. to make teflon

  4. to cut a round sheet of teflon that exactly fits
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Teflon even when melted do not flow instead it behaves as a gel due to absence of crystalline phase and high melting point so manufactures finds a bit difficulty to make teflon stick to metal of pan.

Multiple choice chemistry polymer polymers of commercial importance some commercially important polymers condensation polymers

Identify $X$ in the reaction.


$CHCl _3 \xrightarrow[HF]{SbF _3} CHF _2Cl \overset{1070\, K}{\rightarrow} (X)+2HCl$

  1. $F _2C=CF _2$
  2. $ClFC=CFCl$
  3. $F _2C=CFCl$
  4. $F _2C=CCl _2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When chloroform is treated with antimony trifluoride and $HF$, 2 chlorine atoms are replaced with 2$ F$ atoms. 


When $\displaystyle CHF _2Cl $ is heated to 1070 K, terafluoroethylene (compound X) is obtained. 

$\displaystyle 2CHF _2Cl \xrightarrow {1070K} F _2C=CF _2 $

Multiple choice chemistry carbon and its compounds some important carbon compounds ethanol and ethanoic acid introduction to alcohols - ethanol

Which out of the following has smell similar to that of vinegar?

  1. Methanol

  2. Ethanol

  3. Ethanoic acid

  4. Formic acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Vinegar is a liquid having acetic acid and water as its mixture. So, ethanoic acid is the other name of acetic acid and this smell of vinegar is similar to ethanoic acid. 

Multiple choice chemistry carbon and its compounds some important carbon compounds ethanol and ethanoic acid introduction to alcohols - ethanol

Ethanol is:

  1. ionic compound

  2. noble gas

  3. polar covalent compound

  4. non-polar covalent compound
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ethanol can be written as $CH _3-CH _2-OH$. The oxygen atom in the hydroxyl ($OH$) group is highly electronegative and hence attracts the electrons towards itself. Thus, ethanol is a polar compound with its electrons more towards the oxygen atom. Although ($C _2H _5$) group is non polar.

All the bonds in ethanol are covalent in nature. The bonds are formed by sharing of electrons between the atoms.
Thus, option $C$ is the correct answer.