Description : (4) Liquid Hydrogen + Liquid Oxygen Explanation: LOX and liquid hydrogen, used in the Space Shuttle orbiter, the Centaur upper stage of the Atlas V, Saturn V upper stages, the ... to withstand high combustion pressures and temperatures and they can be regeneratively cooled by the liquid propellant.
Last Answer : The BOD values of water indicate the (1) amount of organic debris (2) amount of oxygen used for biochemical oxidation (3) amount of oxygen used for biochemical reduction (4) amount of ozone used for biochemical oxidation
Description : Which of the following is an Inert Gas? (1) Hydrogen (2) Nitrogen (3) Oxygen (4) Argon
Last Answer : (4) Argon Explanation: Argon is an inert gas (noble gas) that is placed in Group 18 of the periodic table. It is the most abundant noble gas in Earth's crust, comprising 20.00015% of the crust. Helium ... (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn) are other noble gases that occur naturally.
Description : In deep-sea diving, divers use a mixture of gases consisting of oxygen and – (1) hydrogen (2) nitrogen (3) argon (4) helium
Last Answer : (2) nitrogen Explanation: Air is not the "ideal" breathing mixture for diving as with a concentration of approximately 79 percent nitrogen, compressed air poses two potential problems for all divers: ... Nitrox, a gaseous mixture of nitrogen and oxygen. It is also known as 'Enriched Air.'
Description : Which of the following is a noble gas - (1) Argon (2) Hydrogen (3) Oxygen (4) Nitrogen
Last Answer : (1) Argon Explanation: Noble gas, any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table.
Description : In deep-sea diving, divers use a mixture of gases consisting of oxygen and (1) hydrogen (2) nitrogen (3) argon (4) helium
Last Answer : nitrogen
Description : In which of the following groups, are the elements written in the descending order of their respective atomic weights? (a) Nitrogen, carbon, oxygen, hydrogen (b) Oxygen, argon, nitrogen, hydrogen (c) Oxygen, nitrogen, helium, hydrogen (d) Oxygen, nitrogen, helium, bromine
Last Answer : Ans:(c)
Description : Why rockets using liquid hydrogen have higher specific impulse compared to liquid hydrocarbon ?
Last Answer : Liquid hydrogen has higher burning velocity.
Description : Name the gas which is used in balloons in the place of hydrogen? (1) nitrogen (2) helium (3) neorn (4) argon
Last Answer : (2) helium Explanation: Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
Description : A standardized base solution should be protected from which of the following gases? w) hydrogen x) carbon dioxide y) nitrogen z) argon
Last Answer : ANSWER: X -- CARBON DIOXIDE
Description : The most abundant element in the earth's atmosphere is – (1) Argon (2) Nitrogen (3) Oxygen (4) Krypton
Last Answer : (2) Nitrogen Explanation: The most abundant gas in the Earth's atmosphere is nitrogen. Nitrogen makes up 78 percent of the Earth's atmosphere, and it is a permanent gas, which means that its percentage ... atmosphere is made up of 21 percent oxygen, 0.9 percent argon and 0.1 percent trace gases.
Description : The gas used to dilute oxygen for breathing by deep sea divers is- (1) Neon (2) Argon (3) Nitrogen (4) Helium
Last Answer : (4) Helium Explanation: Helium is used since it has very low (almost non-existent) narcotic properties. The nitrogen in air is highly narcotic at depth and adding helium allows one to dive without the effects of narcosis (where one's mind is impaired).
Description : Electric bulbs are filled with – (1) Nitrogen (2) Carbon dioxide (3) Argon (4) Oxygen
Last Answer : (3) Argon Explanation: Argon is produced industrially by the fractional distillation of liquid air. Argon is mostly used as an inert shielding has in welding and other high-temperature industrial processes ... , and other types of gas discharge tubes. Argon makes a distinctive blue-green gas laser.
Description : The most abundant element in the earth’s atmosphere is (1) Argon (2) Nitrogen (3) Oxygen (4) Krypton
Last Answer : Nitrogen
Description : The gas used to dilute oxygen for breathing by deep sea divers is: (1) Neon (2) Argon (3) Nitrogen (4) Helium
Last Answer : Helium
Description : Electric bulbs are filled with : (1) Nitrogen (2) Carbon dioxide (3) Argon (4) Oxygen
Last Answer : Argon
Description : In addition to hydrogen, the other abundant element present on Sun’s surface is - (1) Helium (2) Neon (3) Argon (4) Oxygen
Last Answer : (1) Helium Explanation: The Sun is composed primarily of the chemical elements hydrogen and helium; they account for 74.9% and 23.8% of the mass of the Sun in the photosphere, respectively. All ... out of which it formed: the hydrogen and helium in the Sun were produced by Big Bang nucleosynthesis.
Description : Which of the following elements does not normally occur as a diatomic molecule? w) hydrogen x) chlorine y) argon z) oxygen
Last Answer : ANSWER: Y -- ARGON
Description : In addition to hydrogen, the other abundant element present on Sun’s surface is (1) Helium (2) Neon (3) Argon (4) Oxygen
Description : The gas which turns into liquid at the lowest temperature among the following is – (1) hydrogen (2) oxygen (3) helium (4) nitrogen
Last Answer : (1) hydrogen Explanation: Liquid hydrogen (LH2) is the liquid state, of the element hydrogen. Hydrogen is found naturally in the molecular H2 form. To exist as a liquid, H2 must ... method of obtaining liquid hydrogen involves a compressor resembling a jet engine in both appearance and principle.
Description : The gas which turns into liquid at the lowest temperature among the following is (1) hydrogen (2) oxygen (3) helium (4) nitrogen
Last Answer : hydrogen
Description : Used as fuel in rockets and jets ?
Last Answer : Liquid oxygen is used as fuel in rockets and jets.
Description : Volumetric composition of flue gas analysed with the Orsat apparatus is : CO2 = 12%, O2 = 8%, CO = nil, N2 = 80%. This flue gas composition indicates that (A) Pure oxygen has been used for combustion ... very high (C) Excess air has been used for combustion (D) Hydrogen is not present in the fuel
Last Answer : (C) Excess air has been used for combustion
Description : What of the element out of calcium argon sodium nitrogen oxygen and chlorine can become stable by losing 1 electron?
Last Answer : Sodium. A sodium atom has one valence electron in its 3rd energy level. This is very unstable, so a sodium atom will lose that single valence electron to another atom (nonmetal), and the 2nd energy ... sodium ion, Na+, will bond with a negatively charged ion; either a nonmetal or a polyatomic ion.
Description : Highest percentage of air consists of A. Oxygen B. Carbon dioxide C. Nitrogen D. Argon
Last Answer : C. Nitrogen
Description : Which are the only two elements on the periodic table that are liquid at room temperature? A. Mercury and Bromine (Answer) B. Carbon and helium C. Nitrogen and Hydrogen D. Oxygen and Neon
Last Answer : A. Mercury and Bromine (Answer)
Description : The fuel used in rockets is:
Last Answer : Liquid oxygen, nitrogen tetroxide, and hydrogen peroxide
Description : Margarine is a/an (A) Fat (B) Explosive (C) Plasticiser (D) Rocket propellant
Last Answer : (A) Fat
Description : Hon’ble Raksha Mantri Shri AK Antony, inaugurated DRDO’s state of the art composite propellant processing facility – Advanced Centre for Energetic Materials (ACEM) at Nasik on 29 June 2011. The facility has been setup by (a) VRDE (b) ADE (c) ADA (d) HEMRL
Last Answer : (d) HEMRL
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for Breathing is: (1) Neon (2) Argon (3) Krypton (4) Helium
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing is – (1) Neon (2) Krypton (3) Argon (4) Helium
Last Answer : (4) Helium Explanation: Helium is used by deep sea divers because it reduces the narcosis of nitrogen and it remains below the oxygen toxicity limits. In fact, they use tri mix of Oxygen, helium and a little bit of nitrogen.
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is - (1) Xenon (2) Krypton (3) Argon (4) Helium
Last Answer : (4) Helium Explanation: Trimix is a breathing gas, consisting of oxygen, helium and nitrogen, and is often used in deep commercial diving. The helium is included as a substitute for some ... possible to create mixes suitable for different depths or purposes by adjusting the proportions of each gas.
Description : What will be the molar volume of nitrogen and argon at 273.15 K and 1atm pressure?
Last Answer : Ans. At 273.15K and 1atm pressure every gas has molar volume = 22.4L.
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is (1) Xenon (2) Krypton (3) Argon (4) Helium
Description : Which of the following is not a noble gas? (1) Hydrogen (2) Helium (3) Neon (4) Argon
Last Answer : (1) Hydrogen Explanation: The noble gases are the chemical elements in group 18 of the periodic table. This chemical series contains helium, neon, argon, krypton, xenon, and radon.
Description : Which of the following is not a noble gas ? (1) Hydrogen (2) Helium (3) Neon (4) Argon
Last Answer : Hydrogen
Description : The most abundant constituent of atmospheric air is – (1) carbon (2) hydrogen (3) oxygen (4) nitrogen
Last Answer : (4) nitrogen Explanation: Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
Description : What happens in a reduction reaction? (1) addition of Oxygen (2) addition of Nitrogen (3) addition of Hydrogen (4) None of the above
Last Answer : (3) addition of Hydrogen Explanation: In terms of Oxygen transfer, oxidation is gain of oxygen; reduction is loss of oxygen. However, in terms of hydrogen transfer, oxidation is loss of hydrogen, reduction is gain of hydrogen.
Description : The highest volume of gases in lower atmosphere is comprised of - (1) Hydrogen (2) Carbon dioxide (3) Oxygen (4) Nitrogen
Last Answer : (4) Nitrogen Explanation: There are a number of atmospheric gases which make up air. In the lower atmosphere or troposphere, the main gases are nitrogen and oxygen, which make up 78% and 21% of the volume of air respectively. The remaining 1% of the atmospheric gases is made up of trace gases.
Description : The bubbles in Chanmpagne and Soda are - (1) Nitrogen (2) Oxygen (3) Carbon dioxide (4) Hydrogen
Last Answer : (4) Hydrogen
Description : The most abundant element by number in the living system is : (1) Nitrogen (2) Hydrogen (3) Oxygen (4) Carbon
Last Answer : (2) Hydrogen Explanation: In sequential order, Hydrogen. Oxygen, Carbon and Nitrogen are the most abundant elements by number in the living system. Hydrogen constitutes 49.8% of living systems, while Oxygen ... . It is not surprising, therefore, that the living cell is between 60% and 90% water.
Description : Silver gets corroded due to ______ in air. (1) Oxygen (2) Hydrogen Sulphide (3) Carbon dioxide (4) Nitrogen
Last Answer : (2) Hydrogen Sulphide Explanation: Silver is a fairly stable metal and under normal circumstances does not corrode quickly. However, it is particularly susceptible to the effects of the sulfide ... atmosphere, especially in marine environment, and readily forms a surface tarnish of silver sulphide.
Description : The name of unreactive gas is – (1) Carbon dioxide (2) Hydrogen (3) Nitrogen (4) Oxygen
Last Answer : (3) Nitrogen Explanation: Nitrogen is chemically unreactive because it has a strong triple bond which binds the two nitrogen atoms together making it harder for it to be broken. It does not burn, and at ordinary temperatures it does not react with other elements.
Description : The gas that is used in the manufacture of vanaspati ghee is - (1) Oxygen (2) Carbon dioxide (3) Hydrogen (4) Nitrogen
Last Answer : (3) Hydrogen Explanation: Hydrogenation - to treat with hydrogen - is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst. ... is for the processing of vegetableoils (fats to give margarine and related spreads and shortenings).
Description : Which of the following gases is mixed with oxygen for breathing by divers in aqualungs? (1) Methane (2) Nitrogen (3) Helium (4) Hydrogen
Last Answer : (2) Nitrogen Explanation: For some diving, has mixtures other than normal atmospheric air (21 % oxygen, 78% nitrogen, 1% trace gases) can be used, so long as the diver is properly ... reducing the likelihood of decompression sickness or allowing longer exposure to the same pressure for equal risk.
Description : Which one of the following is a microelement? (1) Chlorine (2) Hydrogen (3) Nitrogen (4) Oxygen
Last Answer : (1) Chlorine Explanation: In analytical chemistry, a trace element or micro-element is an element in a sample that has an average concentration of less than 100 parts per million measured in atomic count or less than ... Cu), iron (Fe), chloride (C1), manganese (Mn), molybdenum (Mo) and zinc (Zn).
Description : The major constituent of air is – (1) nitrogen (2) carbon dioxide (3) oxygen (4) hydrogen
Last Answer : (1) nitrogen Explanation: Depending on various geographical locationsthese may change, but for the most part air is made up of 78% nitrogen (N2), 21% oxygen (O2), and trace amounts of ... and mostly inert diatomic gas at standard conditions, constituting 78.09% by volume of Earth's atmosphere.
Description : Ozone consists of - (1) Oxygen only (2) Oxygen and Nitrogen (3) Hydrogen and Carbon (4) Oxygen and Carbon
Last Answer : (1) Oxygen only Explanation: Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the ... and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
Description : Carbon monoxide is an inflammable gas. Which one of the following is also inflammable? (1) Helium (2) Nitrogen (3) Oxygen (4) Hydrogen
Last Answer : (4) Hydrogen Explanation: At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular ... important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.