Chemistry Test-27

When saturated vapour is compressed it's composition (liq-vapour)changes which make sure that pressure remains constant. Saturated Vapour doesn't obey ideal gas law.

Freons are chlorofluorocarbons and are responsible for the depletion of the ozone layer in the upper strata of the atmosphere. They are used as propellants in aerosol spray cans, refrigerators, fire fighting reagents, etc. They are stable compounds and are chemically inert. They do not react with any substance with which they come in contact and thus float through the atmosphere unchanged and eventually enter the stratosphere. There they absorb UV radiations and break down liberating free atomic chlorine which causes decomposition of ozone. This results in the depletion of the ozone layer.

\(\dot{ Cl }+ O _{3} \rightarrow Cl \dot{ O }+ O _{2} \)

\( ClO + O _{3} \rightarrow \dot{ Cl } +2 O _{2}\)

Alkaline earth metals include group \(2\) elements.

The elements present in the second group of the periodic table are known as alkaline earth metals. This group includes six elements.They are called alkaline earth metals because they form alkaline solutions and hydroxides when they react with water.

The alkaline earth metals are placed in the second group from top to bottom in the order:

Alkaline-earth metal, any of the six chemical elements that comprise Group \(2\) (IIa) of the periodic table. The elements are

1. Beryllium \( (Be)\)
2. Magnesium \( (Mg)\)
3. Calcium \( (Ca)\)
4. Strontium \(( Sr )\)
5. Barium \( (Ba)\)
6. Radium ( \(Ra )\)

Seldane is an antihistamine. Antihistamines prevent sneezing, runny nose, itching and watering of the eyes, and other allergic symptoms.

Seldane is used to treat allergies, hives (urticaria), and other allergic inflammatory conditions.

An acid is a substance that produces hydrogen ions in a water solution.

Clouds can be made to cause rain by spraying oppositely charged colloidal dust, sand particles, or precipitates of silver iodide over them. This causes a neutralization reaction between the two colloids and results in the coagulation of water droplets that come down as rain.

When the cells are grown on a carbon source different than glucose, then polysaccharides are synthesized using a different pathway. Gluconeogenesis (abbreviated GNG) is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as phosphoenolpyruvate (PEP).

Aspirin and paracetamol belong to the class of non-narcotic analgesics. Aspirin is the most familiar example. Aspirin inhibits the synthesis of chemicals known as prostaglandins which stimulate inflammation in the tissue and cause pain. These drugs are effective in relieving skeletal pain such as that due to arthritis. These drugs have many other effects such as reducing fever (antipyretic) and preventing platelet coagulation. Because of its anti blood clotting action, aspirin finds use in prevention of heart attacks.

According to Le-Chatelier's principle increase in temperature favours the endothermic reaction while a decrease in temperature favour the exothermic reaction. Increase in pressure shifts the equilibrium in that side in which the number of moles of gaseous species decreases.

Note: An endothermic reaction is accompanied by the absorption of heat whereas an exothermic reaction is accompanied by the evolution of heat.

When the temperature is increased for an endothermic reaction, the added heat is absorbed during the forward reaction. Total amount of heat in the system thus decreases and the temperature decreases. This nullifies the effect of increase in temperature. So, the increase in temperature favours the endothermic reaction.

Inside cilia and flagella is a microtubule-based cytoskeleton called the axoneme. The axoneme of primary cilia typically has a ring of nine outer microtubule doublets (called a 9+0 axoneme), and the axoneme of a motile cilium has two central microtubules in addition to the nine outer doublets (called a 9+2 axoneme).The axonemal cytoskeleton acts as a scaffolding for various protein complexes and provides binding sites for molecular motor proteins such as kinesin-2, that help carry proteins up and down the microtubules.