NCERT Solutions for Class 12 Chemistry Part 1 Chapter 16
Chemistry in Everyday Life Class 12
Chapter 16 Chemistry in Everyday Life Exercise Solutions
In text : Solutions of Questions on Page Number : 448
Sleeping pills are recommended by doctors to the patients suffering from sleeplessness but it is not advisable to take its doses without consultation with the doctor, Why?
With reference to which classification has the statement, 'ranitidine is an antacid" been given?
Why do we require artificial sweetening agents?
Write the chemical equation for preparing sodium soap from glyceryl oleate and glyceryl palmitate. Structural formulae of these compounds are given below.
(ii)
Q5 :
Functional groups present in the molecule are:
(i) Ether, and
(ii)
Exercise : Solutions of Questions on Page Number : 454
Why do we need to classify drugs in different ways?
The classification of drugs and the reasons for classification are as follows:
This classification provides doctors the whole range of drugs available for the treatment of a particular type of problem. Hence, such a classification is very useful to doctors.
This classification is based on the action of a drug on a particular biochemical process. Thus, this classification is important.
This classification provides the range of drugs sharing common structural features and often having similar pharmacological activity.
Explain the term target molecules or drug targets as used in medicinal chemistry.
In medicinal chemistry, drug targets refer to the key molecules involved in certain metabolic pathways that result in specific diseases. Carbohydrates, proteins, lipids, and nucleic acids are examples of drug targets.
Name the macromolecules that are chosen as drug targets.
The macromolecules chosen as drug targets are carbohydrates, lipids, proteins, and nucleic acids.
Answer :
Define the term chemotherapy.
Which forces are involved in holding the drugs to the active site of enzymes?
Either of the following forces can be involved in holding drugs to the active sites of enzymes.
(i) Ionic bonding
(ii) Hydrogen bonding
(iii) Dipole - dipole interaction
(iv)
While antacids and antiallergic drugs interfere with the function of histamines, why do these not interfere with the function of each other?
Low level of noradrenaline is the cause of depression. What types of drugs are needed to cure this problem? Name two drugs.
Anti-depressant drugs are needed to counteract the effect of depression. These drugs inhibit enzymes catalysing the degradation of the neurotransmitter, noradrenaline. As a result, the important neurotransmitter is slowly metabolised and then it can activate its receptor for longer periods of time.
Two anti-depressant drugs are:
(i) Iproniazid
(ii)
What is meant by the term 'broad spectrum antibiotics'? Explain.
Antibiotics that are effective against a wide range of gram-positive and gram-negative bacteria are known as broad spectrum antibiotics. Chloramphenicol is a broad spectrum antibiotic.
It can be used for the treatment of typhoid, dysentery, acute fever, pneumonia, meningitis, and certain forms of urinary infections. Two other broad spectrum antibiotics are vancomycin and ofloxacin. Ampicillin and amoxicillin - synthetically modified from penicillin - are also broad spectrum antibiotics.
How do antiseptics differ from disinfectants? Give one example of each.
Antisepticsand disinfectants are effective against micro-organisms. However, antiseptics are applied to the living tissues such as wounds, cuts, ulcers, and diseased skin surfaces, while disinfectants are applied to inanimate objects such as floors, drainage system, instruments, etc. Disinfectants are harmful to the living tissues.
Why are cimetidine and ranitidine better antacids than sodium hydrogen carbonate or magnesium or aluminium hydroxide?
Antacids such as sodium hydrogen carbonate, magnesium hydroxide, and aluminium hydroxide work by neutralising the excess hydrochloric acid present in the stomach. However, the root cause for the release of excess acid remains untreated.
Name a substance which can be used as an antiseptic as well as disinfectant.
What are the main constituents of dettol?
The main constituents of dettol are chloroxylenol and α-terpineol.
What is tincture of iodine? What is its use?
What are food preservatives?
Why is use of aspartame limited to cold foods and drinks?
What are artificial sweetening agents? Give two examples.
Name a sweetening agent used in the preparation of sweets for a diabetic patient.
What problem arises in using alitame as artificial sweetener?
How are synthetic detergents better than soap?
Soaps work in soft water. However, they are not effective in hard water. In contrast, synthetic detergents work both in soft water and hard water.
Explain the following terms with suitable examples
(ii) Anionic detergents and
Answer :
Cationic detergents are quaternary ammonium salts of acetates, chlorides, or bromides. These are called cationic detergents because the cationic part of these detergents contains a long hydrocarbon chain and a positive charge on the N atom.
For example: cetyltrimethylammonium bromide
Anionic detergents are of two types:
1.
3 3
Sodium
alkyl sulphates: These detergents are sodium salts of
long chain alcohols. They are prepared by first
treating these alcohols with concentrated
sulphuric acid and then with sodium hydroxide. Examples
of these detergents include
sodium lauryl sulphate
(C11H23CH2OSO -Na+) and sodium
stearyl sulphate (C17H35CH2OSO -Na+).
2. Sodium alkylbenzenesulphonates: These detergents are sodium salts of long chain alkylbenzenesulphonic acids. They are prepared by Friedel-Crafts alkylation of benzene with long chain alkyl halides or alkenes. The obtained product is first treated with concentrated sulphuric acid and then with sodium hydroxide. Sodium 4-(1-dodecy) benzenesulphonate (SDS) is an example of anionic detergents.
What are biodegradable and non-biodegradable detergents? Give one example of each.
Detergents that can be degraded by bacteria are called biodegradable detergents. Such detergents have straight hydrocarbon chains. For example: sodium lauryl sulphate
Why do soaps not work in hard water?
Can you use soaps and synthetic detergents to check the hardness of water?
Soaps get precipitated in hard water, but not in soft water. Therefore, soaps can be used for checking the hardness of water.
Explain the cleansing action of soaps.
If water contains dissolved calcium hydrogen carbonate, out of soaps and synthetic detergents which one will you use for cleaning clothes?
Synthetic detergents are preferred for cleaning clothes. When soaps are dissolved in water containing calcium ions, these ions form insoluble salts that are of no further use.
However,when synthetic detergents are dissolved in water containing calcium ions, these ions form soluble salts that act as cleansing agents.
Label the hydrophilic and hydrophobic parts in the following compounds.
(ii)
Answer :
(ii)