Chemistry

Chemical Compounds and Reactions

505 Questions

Chemical compounds and reactions involve understanding the properties, colors, and formation of various chemical substances. Questions focus on identifying precipitates, observing color changes during reactions, and naming common compounds. This topic is a fundamental part of the chemistry syllabus for competitive exams.

identifying precipitateschemical reaction colorscompound namingcolloidal particle propertiesacid base reactions

Chemical Compounds and Reactions Questions

Multiple choice

The main constituents of LPG gas are

  1. butane and propane

  2. methane and carbon dioxide

  3. water vapour and carbon monoxide

  4. All of the above

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Butane and propane are the main constituents of LPG gas.

Multiple choice

Flame retardants are chemicals that inhibit or resist the spread of fire. Which of the following substances is primarily used as a flame retardant ?

  1. Zinc acetate

  2. Zinc ammonium chloride

  3. Zinc antimonide

  4. Zinc borate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Zinc borate is an inorganic compound, a borate of zinc. It is a white crystalline or amorphous powder insoluble in water. Its toxicity is low. Its melting point is 980 °C. It is primarily used as a flame retardant in plastics and cellulose fibers, paper, rubbers and textiles.

Multiple choice

Which of the following metallacycles has the formula LnM(CH)4?

  1. Metallacyclobutanes

  2. Metallacyclopentadienes

  3. Metallacyclopentanes

  4. Metallabenzenes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The parent metallacyclopentadiene has the formula LnM(CH)4. Most arise from the coupling of two alkynes at a low valent metal centres such as derivatives of Co(I) and Zr(II). Late metal derivatives (Co, Ni) are intermediates in the metal-catalysed trimerization of alkynes to arenes. For example, the zirconacyclopentadiene Cp2ZrC4Me4 is a useful carrier for C4Me4 2- .

Multiple choice

Who among the following prepared borazine?

  1. Stock and Pohland

  2. Stock

  3. Allen and Senoff

  4. Cotton

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct,  because Stock and Pohland (1921) prepared borazine by the reaction of diborane and ammonia at -120 ˚C. In this reaction diammoniate of diborane is formed, which on decomposition at 200 ˚C gives borazine