Chemistry in Daily Life Online Test 7th Science Lesson 15 Questions in English

Explanation

ORS (Oral Rehydration Solution) is a special combination of dry salts that is mixed with safe water. It can help to replace the fluids lost due to diarrhoea.

Explanation

During the Bangladesh liberation war, Therapy with Oral Rehydration Solution (ORS) in 1971 reduced cholera death rates from 50% to 3% among thousands of refugees.

Explanation

An Indian doctor, Dilip Mahalanabis, had to manage the shortage of saline bottles and coup up with the dehydration faced by the refuges. Dr Dilip Mahalanabis showed the efficacy of ORS in cholera cases among Bangladeshi refugees (1971-72). Further field trial during the cholera epidemic in Manipur attested to its efficacy, ORS has since saved the lives of millions of children around the world.

Explanation

The field trial during the cholera epidemic in Manipur attested to its efficacy, ORS has since saved the lives of millions of children around the world.

Explanation

In the normal healthy intestine, there is a continuous exchange of water through the intestinal wall. Up to 20 litres of water is secreted and very nearly as much is reabsorbed every 24 hours. This mechanism allows the absorption of soluble metabolites into the bloodstream from digested food.

Explanation

In a state of diarrheal disease there is imbalance and much more water is secreted than reabsorbed causing a net loss to the body which can be as high as several litres a day. In addition to water loss, sodium and potassium are also lost.

Explanation

The saline bottle directly transfers water and sodium into the blood stream. However, for the saline water is administered through mouth, intestinal wall, is a not able to absorb neither water nor sodium. Dr Dilip Mahalanabis found that if glucose (sugar) is added to the salt solution, then all the three- water, sodium and glucose are absorbed by the body.

Explanation

Certain concentration of sodium (Na) is needed for proper functioning of the body For, example, only with adequate sodium concentration in the intestinal wall, water can be absorbed by it through a process known as osmosis. If there is inadequate salt in the intestinal wall the body will not be able to absorb water. Through the process of osmosis, the salts and sugars pull water into your bloodstream and speed up rehydration.

Explanation

Let us see homely made of ORS, be very careful to mix 6 level teaspoons of sugar and 1/2 level teaspoon of salt dissolved in 1 litre of clean water. Too much sugar can make diarrhea worse. Too much salt can be extremely harmful to the child. Making the mixture a little too diluted (with more than 1 litre of clean water) is not harmful.

Explanation

Acidity is a set of symptoms caused by excess production of acid by the gastric glands of the stomach.

Explanation

Your stomach naturally produces gastric or hydrochloric acid (HCl) to help digest and break down food. Acidity issues arise when there is excess production of this acid due to triggers such as acidic foods, spicy food, alcohol, dehydration and stress. When acidity occurs, the excess acid may move up from your stomach to your oesophagus.

Explanation

The lining of your stomach with a pH of 1 to 3 is designed as such to withstand a high acidic environment

Explanation

When we have acidity or heartburn, we are administered a class of medicines known as antacids. They are actually weak bases. As learned in chemistry, when a base is mixed with an acid a neutralization reaction occurs. When antacids are consumed, it creates a chemical reaction in the stomach lowering the acidity and makes the digestive acids less corrosive and damaging.

Explanation

Most of the common antacids are Sodium Bicarbonate (NaHCO3), Calcium Carbonate (CaCO3), Magnesium Hydroxide (Mg (OH)2), Magnesium Carbonate (MgCO3) and Aluminium Hydroxide

Al (OH)3. The chemical reaction created when Magnesium Hydroxide neutralizes HCI in the stomach and intestine

Explanation

The discovery of antibiotics was an accident, which happened in 1928 while a British bacteriologist, Dr Alexander Fleming

Explanation

Dr Alexander Fleming was involved in research on staphylococcus bacteria, he developed antibiotics. This bacterium was meant to cause deadly diseases such as pneumonia, sour throat, etc.

Explanation

Fleming identified that the “mould juice” was capable of killing a wide variety of harmful bacteria, such as streptococcus, meningococcus and diphtheria bacillus.

Explanation

The world first antibiotics is penicillin discovered by Alexander Fleming.

Explanation

Fleming was not the first using moulds and other living micro-organisms to treat infections. Thousands of years ago, the ancient Egyptians, had used mouldy bread to treat infected wounds. Similar practices were observed among ancient Greeks, Serbians and even among Indians. While these were perhaps partially effective, their efficacy is nowhere near the modern antibiotics.

Explanation

Fleming named the mould penicillium notatum, from which the antibiotic penicillin was isolated.

Explanation

Naturally, many micro-organisms and plants synthesize chemicals which are toxic in nature to protect them from invading organisms. The biosynthesized chemicals isolated from the plants/micro-organisms and used as medicines against infectious diseases. These substances were called as antibiotics. Ex: Chloramphenicols, tetracyclines, Penicillin derivatives, cephalosporin’s and their derivatives. Today, many infectious diseases in the world are rare due to the advancement in research.

Explanation

Antibiotics don’t work for viruses like cold and the flu. The over use of antibiotics makes it inactive or less effective. Antibiotic resistance is defi ned as the ability of the microorganisms to resist the effects of an antibiotic to which they were once sensitive.

Explanation

Brain can trigger to release pain suppressing chemical and additional flow of additional white blood cells and platelets to help repair tissue at an injury site

Explanation

Analgesics or pain killers are the pain suppressing chemicals released by the body. They suppress the feeling of ‘pain’. These analgesics drug selectively relieves pain by acting either in CNS (Central Nerves System) or on peripheral pain mechanism, without significantly altering consciousness.

Explanation

When we are affected by fever, often we are administered Paracetamol. Paracetamol interact with the receptors and reduce the intensity of pain signals to the brain, also suppresses the release of substances, called prostaglandins that increase pain and body temperature.

Explanation

The first local anaesthetic was cocaine was isolated from coca leaves.

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The first local anaesthetic was cocaine was isolated from coca leaves by Albert Nieminen Germany, 1860.

Explanation

The first local anaesthetic was cocaine was isolated from coca leaves by Albert Nieminen Germany, 1860.

Explanation

Traditional anti-inflammatory agents are classified into two types. i) Non – narcotic and ii) Narcotic drugs.

Explanation

Carfentanil is a narcotic drug.

Explanation

In normal course our body temperature is ranges from 98.4 to 98.6 degrees Fahrenheit. When the temperature goes above this level it is called fever. Most common cause of fever is infection. Bacteria and virus cannot thrive above a certain temperature. To defend the invading virus and bacteria the immunity system increases the body temperature.

Explanation

Once infection is sensed, the immune system releases a chemical called pyrogen. These pyrogens released into bloodstream reaches the hypothalamus, present at the basal part of the brain. The function of Hypothalamus is to control the body temperature.

Explanation

Sensing the pyrogens, hypothalamus increases the body temperature by releasing a chemical called prostaglandin.

Explanation

Normally little fever is good as it helps to arrest the growth of infection. However, if the internal body temperature exceeds 105°F, this may cause damage to our body protein and the brain may experience seizures and delirium. The prolonged high fever may also cause death.

Explanation

Antipyretics (anti – against and pyretic -Feverish) are chemical substances that reduce fever. They suppress the release of prostaglandin and reduce fever.

Explanation

The most common and well known anti pyretic is paracetamol. Other antipyretics and anti- inflammatory agents include Aspirin, Ibuprofen, Diclofenac.

Explanation

Antiseptics are substances applied to the exterior of a body that kill or inhibit microbes and infective agents. Antiseptics can be effective against one or a combination of bacteria, fungi, viruses or other microorganisms.

Explanation

Natural antiseptics are 1. Garlic, 2. Turmeric 3. Aloevera. All antiseptic are disinfectants but not all disinfectants are not antiseptic. Antiseptic can be applied on the live tissues, where disinfectants can be applied on in animate object.

Explanation

Dettol is Mixture of chloroxylenol and terpincol.

Explanation

Tincher ingredients are Iodine + 2 to 3% alcohol – Water mixture Soap, Iodoform, phenolic solutions, ethanol, Boric acid, are examples.

Explanation

This stimulates many smooth muscles to contract, such as gastrointestinal tract and bronchi. In certain smooth muscles, they cause relaxation of blood capillaries which increase the flow of  lymph and its protein content and lead to the formation of edema (redness and rashes).

Explanation

Antihistamines or histamine receptor antagonists oppose selectively all the pharmacological effects of histamines. For, Ex. Diphenhydramine, chlorpheniramine, cimetidine. The adverse effects of antihistamines are mouth dryness and sleepiness.

Explanation

The science or practice of the diagnosis, treatment, and prevention of disease. There are many ways to intake the medicine. 1. Oral use 2. External use 3. Injections (Intra muscular/Intra venous).

Explanation

Can you guess what is common in rusting or iron, burning coal and the flame of candle? They all undergo a chemical reaction known as combustion. Combustion is a chemical reaction that occurs in the presence of a fuel and an oxidizing agent that produces energy, usually in the form of heat and light.

Explanation

What we call as ‘burning’ is really a combustion reaction. In fact, combustion is one of the first chemical reactions intentionally harnessed by humans. Any reaction that involves reaction with oxygen is called oxidation reaction.

Explanation

In the combustion of hydrocarbon with oxygen, typically carbon dioxide and water are produced.

CH4+2O2 → CO2+2H2O+Heat energy.

Explanation

All combustion reactions are exothermic; that is they release heat.

Explanation

The minimum temperature at which a substance catches fire and burns is called its ignition temperature. A substance will not catch fire and burn if its temperature is lower than its ignition temperature. Different substances have different ignition temperatures.

Explanation

Substances which have very low ignition temperature and can easily catch fire with a flame are called inflammable substances. E g. Petrol. Alcohol, LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), etc.

Explanation

Flame is a zone of combustions of a combustible substance. Substances which vaporize during burning produce flames.

Explanation

Flame is actually a chemical reaction. To be specific, the flame is a mixture of gases (vaporized fuel, oxygen, carbon dioxide, carbon monoxide, water vapor, and many volatile materials) and so is matter. The light and heat produced by the flame is energy, not matter. But fire is a matter. A candle flame is caused by vapour burning above the candle. This burning vapour is hotter than the surrounding air and is therefore less dense. So, by the principle of convection, it “rises” so the flame is always upwards.

Explanation

Substances which do not vaporize during burning do not produce flames e g. coal. Wax and Kerosene produce flame.

Explanation

White flame – Epsom salt (MgSO4 ) • Violet flame – Lithium Chloride • Blue flame – Bleaching powder • Green flame – Borax powder • Yellow flame – Calcium chloride.

Explanation

The outer zone – complete combustion of the fuel takes place and the colour of the flame is blue and is the hottest part of the flame. It is the non-luminous part of the flame.

The middle zone -partial combustions of the fuel takes place and the colour of the flame is yellow and is moderately hot part of the flame. It is the luminous part of the flame.

Explanation

The amount of heat energy produced on complete combustion of 1kg of fuel is called its calorific value.

Explanation

Table salt produce orange flame if soaked in alcohol and makes fire.

Explanation

The calorific value of a fuel is expressed in a unit called kilo joule per kg (kJ/kg).

Explanation

Calorific value = Amount of fuel used for burning in kJ/kg × Heat produced.

If 4.5kg of fuel is completely burnt and the amount of heat produced stands measured at 1, 80,000 kJ what is its calorific value. Calorific value = 1, 80,000 / 4.5 = 40,000 KJ/Kg.

Explanation

Strontium chloride produce red flame if soaked in alcohol and makes fire. Potassium Chloride produce Indigo Flame.

Explanation

There are three main types of combustion. They are, 1. Rapid combustion, 2. Spontaneous combustion and 3. Explosion.

Explanation

Spontaneous combustion: Is combustion process in which a light without the help of external heat.eg. Phosphorus burns spontaneously at room temperature.

Explanation

Methane (500000) has highest calorific value followed by diesel (450000) and hydrogen (150000).

Explanation

Characteristics of good fuel are 1. Readily available 2. Cheap 3. Easy transport and store 4. Burns at moderate rate 5. Produce large amount of heat 6. Do not leave behind any undesirable substances. And 7. Does not cause pollution.

Explanation

Slow combustion is a form of combustion which takes place at low temperatures. Respiration is an example of slow combustion.

Explanation

Th e conditions necessary for producing fire are, 1. Fuel 2. Air (to supply oxygen) and 3. Heat (to raise the temperature of the fuel beyond its ignition temperature). Fire can be controlled by removing any one or more of these conditions.

Explanation

Explanation

The most common types of fire extinguishers are, 1. Air pressurized water extinguishers, 2. Carbon- di-oxide extinguishers and 3. Dry chemical powder extinguishers.

Explanation

Combustible materials: caused by flammable solids, such as wood, paper, and fabric

Explanation

Flammable gases: like hydrogen, butane or methane.

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Flammable liquids: such as petrol, turpentine or paint.

Explanation

Fire extinguishers can be broadly classified into five types: 1. Water, 2. Foam, 3. Dry Powder, 4. CO2, 5. Wet Chemical.

Explanation

Combustible metals: chemicals such as magnesium, aluminium or potassium.

Explanation

There are five classes of fire: Class A, Class B, Class C, Class D, and Class E.