Chemistry MCQs with answers Page - 16

The given principle is one of the postulates of the Dalton’s atomic theory given in 1803 by John Dalton. The postulates of Dalton’s atomic theory are as follows:
1. Elements consist of indivisible small particles (atoms).
2. All atoms of the same element are identical; different elements have different types of atom.
3. Atoms can neither be created nor destroyed.
4. ‘Compound elements’ (i.e. Compounds) are formed when atoms of different elements join in simple ratios to form ‘compound atoms’ (i.e. Molecules).

Sodium benzoate is added to soft drinks as preservative. Benzene in soft drinks is of potential concern due to the carcinogenic nature of the benzene molecule. The major cause of benzene in soft drinks is the decarboxylation of benzoic acid in the presence of ascorbic acid (vitamin c). Other factors that affect the formation of benzene are heat and light. Storing soft drinks in warm conditions speed up the formation of benzene.

The oil which contains sulphur amount less than 0.5% is called Sweet Crude Oil. If the Sulphur content is more than 0.5%, it will be called Sour Crude Oil. The Brent crude oil is having around 0.37% Sulphur and that is why Brent Crude Oil is a Sweet crude Oil. Sweet Crude Oil is of High quality, low sulphur crude oil used for processing of gasoline. The more amount of Sulphur in sour crude makes it toxic, and production of Gasoline is more expensive in case of sour crude. The word “sweet” since a gently sweet taste and pleasing aroma due to the little level of Sulfur gives the oil with. The Brent Crude Oil is a sweet crude oil mainly produced in North Sea. It is largest of the several key classifications of crude oil comprising of Ekofisk, Brent Crude, Forties, Brent Sweet Light Crude and Oseberg. Its manufacturer also known as London Brent, Brent petroleum and Brent Blend.

Copper sulphate is used as an algicide for algal growth is copper sulfate. Ozone or Hydrogen peroxide is added to oxidise organic compounds, and thus reduce the amount of coagulant required. Fluoride is a naturally occurring mineral in water and many foods. In addition, fluoride is intentionally added to the public water supplies, because it has been demonstrated that communities with fluoride added to their water supplies have significantly reduced incidence of tooth decay in children. Fluoride makes teeth more resistant to the acid formed by bacteria in the mouth by preventing these acids from removing essential minerals from the tooth surface. Fluoride also helps to repair damaged tooth enamel.