General Science Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination
[A] Amedeo Avogadro
[B] Jons Jacob Berzelius
[C] Marie Curie
[D] Robert Boyle
Jons Jacob Berzelius (1779 – 1848) was a Swedish chemist who is most famous for helping to develop the notation for writing chemical formulas. He also played a role in discovering and isolating many elements including silicon, thorium, cerium, and selenium. Many chemical terms are credited to Berzelius such as “allotrope” and “catalysis.” He is called the father of Swedish chemistry.
[A] John Napier
[B] John Dalton
[C] J. J. Thomson
[D] Michael Faraday
Although Michael Faraday (1791-1867) is primarily known for his research on electromagnetism, he made significant contributions to the field of chemistry, including discovering chlorine and carbon. Faraday also discovered benzene, contributed to the development of electrolysis, and made modern chemistry labs possible by inventing an early Bunsen burner. He is generally considered one of the greatest scientists of all time.
[A] He was the first chairman of University Grants Commission(India)
[B] He was the first director-general of the Council of Scientific and Industrial Research (CSIR)
[C] He is known as Father of research laboratories in India
[D] All are correct
Sir Shanti Swaroop Bhatnagar (1894 – 1955) was a colloid chemist, academic and scientific administrator. He was first director-general of CSIR and first Chairman of the University Grants Commission. He established a total of twelve national laboratories in the country thus winning the epithet of Father of Research Laboratories in India.
[B] Neils Bohr
Electrons revolve around the nucleus in specified circular paths called orbits or shells. Each orbit or shell is associated with a definite amount of energy. Hence these are also called energy levels and are designated K, L, M and N, respectively. The energy associated with a certain energy level increases with the increase of its distance from the nucleus. Hence if the energy associated with the K, L, M and N shells are E1, E2, E3……… respectively, then E1 < E2 < E3 ………. etc. As long as the electron revolves in a particular orbit, the electron does not lose its energy. Therefore, these orbits are called stationary orbits and the electrons are said to be in stationary energy states. An electron jumps from a lower energy level to a higher energy level, by absorbing energy, but when it jumps from a higher to lower energy level, the energy is emitted in the form of electromagnetic radiation. The energy emitted or absorbed (ΔE) is an integral multiple of “hν.”
[A] 2, 18,16
Krypton is a chemical element with symbol Kr and atomic number 36. It is a member of group 18 (noble gases) elements. The electronic configuration of Krypton is [2, 8, 18, 8]
[A] Gastric Juice < Milk Of Magnesia < Citric Juice < Pure Water
[B] Gastric Juice < Citric Juice < Pure Water < Milk Of Magnesia
[C] Citric Juice < Gastric Juice < Pure Water < Milk Of Magnesia
[D] Gastric Juice < Citric Juice < Milk Of Magnesia < Pure Water
[A] Carbon Monoxide
[C] Carbon dioxide
Bread rises due to the process of fermentation, a chemical process by which molecules such as glucose are broken down anaerobically. Fermentation refers to the chemical decomposition of complex organic compounds into simpler substances. With bread, this refers to the process where yeast converts sugar to carbon dioxide and alcohol in the absence of oxygen, causing the dough to rise. During the process of dough fermentation, we turn a sticky mess of dough into a well-supported structure, which looks and smells delicious. It starts with water, flour and yeast. Once these are combined in the mixing bowl, the fermentation begins. The longer the process continues the effects of it become more powerful. Hydrated flour develops into gluten. The process of yeast acting on the starches in the flour creates gas. The gas gets trapped between strands of gluten which forms pockets of air. The air pockets expand which force the dough rise. Larger air pockets make a more open crumb and lighter textured bread. The creation of lactic and acetic acids condition the dough. Organic acids create flavour, enhance the dough handling properties and extend the keeping qualities of the bread. Ethanol produced in the process of creating carbon dioxide gas will largely evaporate when baked though traces remain to support odour, flavour and keeping quality.
[C] Brick Red
[D] Crimson Red
A flame test is performed by introducing a sample into the blue flame of a bunsen burner and noting any change in the colour of the flame. The tests can be used to detect the presence of some metallic elements in salts. The flame test is an analytical chemistry method used to help identify metal ions. While it’s a useful qualitative analysis test—and a lot of fun to perform—it can’t be used to identify all metals because not all metal ions yield flame colours. Also, some metal ions display colours that are similar to each other making it hard to tell them apart. Nevertheless, the test is still useful for identifying numerous metals and metalloids. The flame test is all about thermal energy, electrons, and the energy of photons. The colours observed during the flame test result from the excitement of the electrons caused by the increased temperature. The electrons “jump” from their ground state to a higher energy level. As they return to their ground state, they emit visible light. The colour of the light is connected to the location of the electrons and the affinity the outer-shell electrons have to the atomic nucleus. The colour emitted by larger atoms is lower in energy than the light emitted by smaller atoms. So, strontium (atomic number 38) produces a crimson reddish colour. With strontium salt, the colour of Bunsen flame ranges from crimson to red.
[B] Carbon dioxide
[C] Carbon Monoxide
[D] Chloro fluorocarbons
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. The primary greenhouse gases in the Earth’s atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone. Nitrous oxide (N2O) gas should not be confused with nitric oxide (NO) or nitrogen dioxide (NO2). Neither nitric oxide nor nitrogen dioxide is greenhouse gases, although they are important in the process of creation of tropospheric ozone which is a greenhouse gas. There are several sources of nitrous oxide, both natural and anthropogenic (human), to the atmosphere with many of these sources difficult to measure. Because of this, there is general agreement that the atmospheric sources and sinks of nitrous oxide are difficult to bring into balance.
Which of the following is an aluminium ore?
Bauxite is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite, boehmite and diaspore, in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO2. Bauxite was named after the village Les Baux in southern France, where it was first recognized as containing aluminium and named by the French geologist Pierre Berthier in 1821.