Chemistry MCQs

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Imbibition is the process of absorption of water by substances without forming a solution. Swelling of seeds when immersed in water is an example of imbibition. Imbibition is the temporary increase in the volume of the cell.

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Carbon dioxide has one carbon atom and two oxygen atoms, and a molecular weight of 44 grams per mole. The oxygen in the air is actually O2, or molecular oxygen, with a molecular weight of 32. Hence, carbon dioxide has a higher density, or is heavier than oxygen.

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• Lactic acid is found primarily in sour milk products, such as koumiss, laban, yogurt, kefir, and some cottage cheeses.
• Vinegar is 5% acetic acid. Acetic acid is a compound that, when pure, is water clear and freezes just above room temperature.
• Lemon juice and lime juice are rich sources of citric acid, containing 1.44 and 1.38 g/oz, respectively.
• Butyric acid is a fatty acid occurring in the form of esters in animal fats. The triglyceride of butyric acid makes up 3–4% of butter.

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Methyl alcohol is very dangerous. May be fatal or cause blindness if swallowed. Harmful, if inhaled or absorbed through skin. It cannot be made non poisonous. Some other harmful effects are results into irritation of skin, eyes and respiratory track. It can also effects central nervous system and liver.

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The bonds in these diatomic molecules are non-polar covalent single bonds. However, halogens readily combine with most elements and are never seen uncombined in nature. As a general rule, fluorine is the most reactive halogen and astatine is the least reactive.

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Allotropes are the elements of same atom existing in different forms. Allotropes of carbon are Diamond, Graphite, Graphene, Fullerene, lonsdaleite, carbon nanotube etc.

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Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2. 1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.

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Antoine Lavoisier was a French nobleman and chemist who was central to the 18th-century chemical revolution and who had a large influence on both the history of chemistry and the history of biology. He is widely considered in popular literature as the “father of modern chemistry”. Lavoisier is most noted for his discovery of the role oxygen plays in combustion. He recognized and named oxygen and hydrogen.

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An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working.

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When an atom is attracted to another atom because it has an unequal number of electrons and protons, the atom is called an ion. If the atom has more electrons than protons, it is a negative ion, or Anion. If it has more protons than electrons, it is a positive ion (cation).