UKPCS Science Chemistry: CEMENT#17

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

Cement is a binder, a substance used in construction that sets, hardens and adheres to other materials, binding them together. Cement is seldom used solely, but is used to bind sand and gravel (aggregate) together. Cement is used with fine aggregate to produce mortar for masonry, or with sand and gravel aggregates to produce concrete.

Cements used in construction are usually inorganic, often lime or calcium silicate based, and can be characterized as being either hydraulic or non-hydraulic, depending upon the ability of the cement to set in the presence of water (see hydraulic and non-hydraulic lime plaster). Continue reading “UKPCS Science Chemistry: CEMENT#17”

UKPCS Science Chemistry: Lime #15

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

LIME

Lime is a calcium-containing inorganic material in which carbonates, oxides, and hydroxides predominate. In the strict sense of the term, lime is calcium oxide or calcium hydroxide. Continue reading “UKPCS Science Chemistry: Lime #15”

UKPCS Science Chemistry: Plaster of Paris #14

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

PLASTER OF PARIS

Gypsum plaster, or plaster of Paris, is produced by heating gypsum to about 300 °F (150 °C)

CaSO4·2H2O + heat → CaSO4·0.5H2O + 1.5H2O (released as steam). Continue reading “UKPCS Science Chemistry: Plaster of Paris #14”

UKPCS Science Chemistry: Bleaching Powder #13

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

Bleaching Powder

Calcium hypochlorite is an inorganic compound with formula Ca(ClO)2. As a mixture with lime and calcium chloride, it is marketed as chlorine powder or bleach powder for water treatment and as a bleaching agent. It strongly smells of chlorine, owing to its slow decomposition in moist air. It is not highly soluble in water and is more preferably used in soft to medium-hard water. Continue reading “UKPCS Science Chemistry: Bleaching Powder #13”

UKPCS Science Chemistry: Baking soda #12

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda (sodium carbonate). The natural mineral form is nahcolite. Continue reading “UKPCS Science Chemistry: Baking soda #12”

UKPCS Science Chemistry: Sodium carbonate #11

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

Sodium carbonate (also known as washing soda, soda ash and soda crystals, and in the monohydrate form as crystal carbonate), Na2CO3, is the water-soluble sodium salt of carbonic acid. Continue reading “UKPCS Science Chemistry: Sodium carbonate #11”

UKPCS Science Chemistry: pH,neutral solution,carbonates #7

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

  • pH
    • pH (potential of hydrogen) is a scale of acidity from 0 to 14. It tells how acidic or alkaline a substance is.
    • More acidic solutions, have lower pH. More alkaline solutions, have higher pH. Substances that aren’t acidic or alkaline (that is, neutral solutions) usually have a pH of 7.
    • Acids have a pH that is less than 7. Alkalis have a pH that is greater than 7.pH is a measure of the concentration of protons (H+) in a solution.
    • Typical indicators are phenolphthalein, methyl orange, methyl red, bromothymol blue, and thymol blue. They each change colour at different points on the pH scale, and can be used together as a universal indicator.
    • Another way is to use litmus paper, which is based on a natural pH indicators.

Continue reading “UKPCS Science Chemistry: pH,neutral solution,carbonates #7”

UKPCS Science Chemistry: Chemical compounds #4

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

CHEMICAL COMPOUNDS

  • Any substance consisting of two or more different types of atoms (chemical elements) in a fixed proportion of its atoms (i.e., stoichiometry) can be termed a chemical compound.
  • Ionic compounds are compounds composed of ions, charged particles that form when an atom (or group of atoms, in the case of polyatomic ions) gains or loses electrons.
  • cationis a positively charged ion
  • An anionis a negatively charged ion.

Continue reading “UKPCS Science Chemistry: Chemical compounds #4”

Target UPSC prelims 2019: Daily MCQs #29

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you daily MCQs.

1. Eyes-on and Hands-off policy” was sometimes seen in the news recently, which is associated with which of the following?
a. Japan‘s amendment of its pacifist constitution
b. India‘s policy on online sale of medicines
c. Policy to protect Sentinelese tribes of India
d. U.S.A‘s policy on migrant children
Continue reading “Target UPSC prelims 2019: Daily MCQs #29”