Q7 of 33 Page 224

Identify the compounds using the clues given below:

i) This is a dark coloured syrupy liquid containing 30% of sucrose.


ii) During manufacture of ethanol this is added as food for yeast.


iii)This enzyme converts sucrose into glucose and fructose.


iv) This compound contains 95.5% ethanol and 4.5% water.


v) This compound contains 100% pure alcohol.


i) Molasses


Explanation: Molasses is a dark coloured syrupy liquid which is used in the manufacture of ethanol.


It contains 30% of sucrose which cannot be separated by the crystallization process.


ii) Nitrogenous matter


Explanation: Molasses usually contain nitrogenous matter which act as food for yeast during fermentation.


iii) Invertase


Explanation: The enzyme invertase present in yeast, bring about the conversion of sucrose into glucose and fructose.



iv) Rectified spirit


Explanation: Rectified spirit is an aqueous solution of ethanol which contains 95.5% of ethanol and 4.5% of water.


v) Absolute alcohol


Explanation: The mixture of “rectified spirit” is heated under reflux over quicklime for about 5 to 6 hours. Then it is allowed to stand for 12 hours.


On distillation of the above mixture, pure alcohol (100%) is obtained. This is called absolute alcohol.


More from this chapter

All 33 →
5

C2H6O is the molecular formula for two compounds A and B. They have different structural formula.

i) What is this phenomenon known as?


ii) Give the structural formula of A and B.


iii) Write down their common and IUPAC names.


iv) Mention the functional groups of A and B.


6

Rewrite the following choosing the correct word from each pair given in brackets:

The hydrocarbons containing at least one carbon to carbon _______________ (double/triple) bond are called __________(alkenes/alkynes).They have the general formula CnH2n.These were previously called ______________(olefins/paraffins). When this compound is treated with ____________(bromine/lime) water, decolourisation occurs because it is _____________(saturated/unsaturated).


8

Read each description given below and say whether it fits for ethanol or ethanoic acid.

i) It is a clear liquid with a burning taste.


ii) It is used to preserve biological specimens in laboratories.


iii) It is used to preserve food and fruit juices.


iv) On cooling, it is frozen to form ice flakes which look like a glacier.


9

Match these words /sentences with appropriate statements given below:

(methanol, fermentation, catenation, homologous series, hydrogen gas)


i) The ability of carbon to form large number of compounds through self-linking property.


ii) Alcohols react with sodium to give this element.


iii) This series helps in giving knowledge and enables systematic study of members.


iv) Formation of simple molecules from complex organic compounds using enzymes.


v) Unlike ethanol, the intake of this compound in very small quantities can cause death.