Samacheer Kalvi 9th Science Solutions Chapter 16 Pdf
Tamilnadu Board Samacheer Kalvi 9th Science Solutions Chapter 16: Tamilnadu State Board Solution Class 9 Science Chapter 16 – APPLIED CHEMISTRY.
Samacheer Kalvi 9th Science Solutions Chapter 16: Overview
Board |
Samacheer Kalvi |
Class |
9 |
Subject |
Science |
Chapter |
16 |
Chapter Name |
APPLIED CHEMISTRY |
Samacheer Kalvi 9th Science Solutions Chapter 16 Pdf
Chapter 16
Applied chemistry
Choose the correct answer.
1) One Nanometer is
(a) 10-7 meter
(b) 10-8 meter
(c) 10-6 meter
(d) 10-9 meter
Ans: (d) 10-9 meter
Because, 1nm = 10-9 m = 10-7 cm
2) The antibiotic Penicillin is obtained from ______________
(a) Plant
(b) Microorganism
(c) Animal
(d) Sunlight
Ans: (b) Microorganism
Because, the Penicillium mold naturally produces the antibiotic penicillin.
3) 1% solution of Iodoform is used as
(a) Antipyretic
(b) Antimalarial
(c) antiseptic
(d) Antacid
Ans: (c) antiseptic
Because, it is used as antiseptic for dressing wounds.
4) The cathode of an electrochemical reaction involves ___________
(a) Oxidation
(b) Reduction
(c) Neutralization
(d) Catenation
Ans: (b) Reduction
Because, electrons flows from anode to cathode and at cathode the ions from the solution receive the electrons. Hence at cathode reduction takes place i.e. gain of electrons takes place.
5) The age of a dead animal can be determined by using an isotope of______________
(a) Carbon
(b) Iodine
(c) Phosphorous
(d) Oxygen
Ans: (a) Carbon
Because, radiocarbon datingis a method by which the age of fossil wood or animal is determined using C-14 isotope.
6) Which of the following does not contain natural dyes?
(a) Potato
(b) Beetroot
(c) Carrot
(d) Turmeric
Ans: (a) Potato
Because, potato does not contains natural dye.
7) This type of food protect us from deficiency diseases.
(a) Carbohydrates
(b) Vitamins
(c) Proteins
(d) Fats
Ans: (b) Vitamins
Because, vitamins from the food protect us from deficiency diseases.
8) Radiochemistry deals with
(a) Oxidants
(b) Batteries
(c) Isotopes
(d) Nanoparticles
Ans: (c) Isotopes
Because, radiochemistry is the branch of chemistry which deals with the study of properties and chemical reactions of non-radioactive isotopes by using the radioactive isotopes of elements.
9) The groups responsible for the color of an organic compound is called
(a) Isotopes
(b) Auxochrome
(c) Chromogen
(d) Chromophore
Ans: (d) Chromophore
Because, chromophore is the group of atoms and electrons which forms the part of the organic molecule which responsible for coloration.
10) Chlorinated hydrocarbons are used as
(a) Fertilizers
(b) Pesticides
(c) Food colorants
(d) Preservatives
Ans: (b) Pesticides
Because, chlorine atoms can easily replace the hydrogen atoms in organic compounds.
Fill in the blanks.
1) _____________ is an electrochemical cell which converts electrical energy into chemical change (Reaction).
Ans: Electrolytic cell is an electrochemical cell which converts electrical energy into chemical change (Reaction).
2) Painkiller drugs are called __________
Ans: Painkiller drugs are called analgesic.
3) Indigo is a _______________ dye.
Ans: Indigo is a vat dye.
Because, it can be used only on cotton and, not on silk and wool. This dyeing is a continuous process and is carried out in a large vessel called vat. So, it is called as vat dye
4) ________, ________ and _________ are macronutrients required for plant growth.
Ans: Nitrogen, Phosphorousand Potassium are macronutrients required for plant growth
5) ______________ is a chemical used in finger print analysis.
Ans: Ninhydrin is a chemical used in finger print analysis.
III. Match the following.
Ans:
Antipyretics: Fever
Corrosion prevention: Electroplating
Hyperthyroidism: Iodine-131
Nanoparticles: Large surface area
Proteins: Body building
Answer briefly.
1) What is Radio Carbon Dating?
Ans: Radioisotopes can be easily detected and estimated quantitatively so they are used in radiochemistry for various applications. Radiochemistry mainly deals with the study of chemical reactions of nonradioactive isotopes using radioactive isotopes. Radiocarbon dating is the method by which the age of fossil wood or animals using C-14 isotope.
2) What are called Anesthetics? How are they classified?
Ans: Anaesthetics are the drugs which causes loss of sensation. This anaesthetics are given to the patients when they undergo surgery. Some are the anaesthetics which lose the sensation of complete body when patients undergo a major surgery in internal organs. And some anaesthetics cause to lose sensation in specific part of the body when patients undergo a minor surgery. On the basis of this there are two types of anaesthetics.
- General anaesthetics:
This are the agents which causes the loss of all modalities of sensation, specifically pain along with the reversible loss of consciousness.
For example: this anaesthetics are given to the patients when they undergo surgery on internal organs, due to which the patient loses consciousness for particular time period and again get it back later.
- Local anaesthetics:
This anaesthetics prevent the pain sensation in localized areas without affecting degree of consciousness.
For example: this kind of anaesthetics are given by dentist to the patients during the minor surgery in teeth.
3) What is the need for chemical fertilizers in crop fields?
Ans: There is a need of chemical fertilizers in crop fields because, this are the chemical compounds added to crop field to supply essential micro and macro nutrients which are required for the growth of crop. Because of the use of fertilizers the growth of crop becomes increased in order to increase the crop yield. For example: ammonium nitrate, calcium phosphate, urea etc. are the fertilizers. We have to use fertilizers singly or in the form of mixture depending on the nature of the soil.
4) What is Forensic chemistry related to?
Ans: Forensic chemistry applies scientific principles, techniques, and methods to the investigation of crime. The daily causing crimes like robbery, murder, sexual harassment etc. this type of crimes are solved by applying forensic chemistry rules. It has vast of applications in criminal investigations. The methods of forensic chemistry used in criminal investigations are finger print, biometrics and alcohol test etc.
Answer in detail.
1) Explain the types of dyes based on their method of application.
Ans: The organic compounds which are used as colourants are called dyes. These dyes are all aromatic compounds, originating from plants and also from insects, fungi and lichens. All the coloured compounds are not the dyes, dyes are those coloured compounds which firmly fixed with fabrics by chemical or physical bonding. They are having particular characteristics properties. They must possess suitable colour. They must have ability to fix within the fabrics and fast to light. They have the property to resist the action of water, dilute acids and alkalis.
On the basis of method of application dyes are classified as follows:
- Acid dyes: This type of dyes are acidic in nature and used for dyeing animal fibers and synthetic fibers. They can be used for protein fibers like wool and silk. For example: picric acid, Napthol yellow-s
- Basic dyes: This dyes contains the basic group like -NH2,- NHR, – NR2 etc. They are used for dyeing animal fibers and plant fibers.
- Mordant dyes or indirect dyes: They are having a little affinity for cotton fabrics and due to which do not dye directly. For this they require pretreatment of the fiber with the mordant. Aluminum, chromium and iron salts are used as mordant. For example: Alizarin.
- Direct dye: These dyes have very high affinity for cotton, rayon and other cellulose fiber. And hence they are directly applied to the fabric because, they firmly fix on the fabric. For example: Congo red.
- Vat dye: Vat dye is used only on cotton and not on the silk or wool. This dyeing is a continuous process which is carried out in a large vessel called as vat, hence this dyes are called as vat dye. For example: indigo
2) Name various food additives and explain their functions.
Ans: Food additives are mixed with food to keep them fresh and to maintain their color, flavor and also texture.There are different types of food additives which are explained below with their functions.
- Colourants:
This type of food additives are used to color the food.
For example: Carotenoids, Anthocyanin etc.
- Antioxidants: They prevent the oxidation of food. For example: vitamin E, Vitamin C and Carotene etc.
- Preservatives: This type of food additives protect the food from spoilage which happens due to microorganisms. For example: Sodium benzoate, Vinegar etc.
- Artificial sweeteners: This type of food adds sweet taste to food. For example: Saccharin, cyclamate etc.
- Flavor enhancers: This type of food additives are used to enhance or increase the flavor of food. For example: Calcium diglutamate, Monosodium glutamate etc.
Higher Order Thinking Skills.
1) Batteries that are used in mobile phone can be recharged. Likewise, can you recharge the batteries used in watches? Justify your answer.
Ans: There are two types’ cells one is the primary cell and second one is the secondary cell.Primary cells are the cells which are used for single time and cannot be recharged further. This type of cells becomes dead after sometime because the reaction occurring at electrode is happening only one times. So they cannot be reused further. And in watches this type of batteries are used due to we cannot recharge them after use of one time. On the other hand, the secondary cells are the cells which can be recharged repeatedly after its total discharging also. And this type of cells are used in mobile phones. In this cells, the electrical energy is converted into chemical energy when current is passing through it and chemical energy is converted into electrical energy when current is withdrawn from it.
2) Sudha met with a fire accident. What kind of drug(s), she must take?
Ans: Sudha met with an accident so she would have to give analgesics which gives relief from the pain. Because, analgesics are the compounds which relieve all sorts of pains without the loss of consciousness. They are also called as pain killers or pain relievers. Analgesics are given either orally or applied externally. The externally applied analgesics are generally gels. Further she would have to give antibiotics also to protect body from infection of microbes. Because, many microorganisms produces certain chemicals which inhibits the growth or metabolism of the some other disease causing microorganisms. Such chemical compounds are called as antibiotics.
3) The soil pH of a crop land is 5. What kind of fertilizers should be used in that land?
Ans: The ideal soil pH is acidic in nature. The pH of soil is increased by using organic fertilizers which are containing nitrogen. The pH of soil will be increased by increasing the amount of nitrogen in the soil. We have to give the fertilizers containing ammonium nitrate, ammonium sulfate or sulfur coated urea. The pH of the soil should be equal to 6.5. The perfect pH soil increases will the crop yield. So to increase the pH of land, we have to use the organic fertilizers containing nitrogen.