Description : Which was absent in the atmosphere at the time of origin of life? (a) NH3 (b) H2 (c) O2 (d) CH4
Last Answer : O2
Description : Which of the following behaves most closely like an ideal gas? (A) He (B) N2 (C) O2 (D) H2
Last Answer : (A) He
Description : The lightest non-inflammable gas is (A) H2 (B) He (C) Ar (D) O2
Last Answer : Option B
Description : Which of the following gases will effuse out of football bladder most quickly ? (1) He (2) H2 (3) N2 (4) O2
Last Answer : H2
Description : Helium (He), neon (Ne) and argon (Ar) are all colorless, odorless gases with low chemical reactivity. Based on the periodic table, which other element would also have those same properties?
Last Answer : Helium
Description : Identify the substances that are oxidised and the substances which are reduced in the following reactions. (i) 4Na(s) + O2(g) → 2Na2O(s) (ii) CuO (s) + H2(g) → Cu (s) + H2O(l) -Chemistry-10
Last Answer : (i) Substances oxidised is Na as it gains oxygen and oxygen is reduced. (ii) Substances reduced is Cu as hydrogen is oxidised as it gains oxygen.
Description : (a) What are fuel cells? Explain the electrode reactions involved in the working of H2 – O2 fuel cell. (b) Represent the galvanic cell in which the reaction Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s) takes place. -Chemistry
Last Answer : (a) Fuel cells : These cells are the devices which convert the energy produced during combustion of fuels like H2, CH4, etc. directly into electrical energy. The electrode reaction for H2 – O2 fuel cell : (b) The galvanic cell may be represented as Zn (s) | Zn2+ (1M) || Cu2+ (1M) | Cu (s)
Description : Which of the following molecules contains a polar covalent bond A.H2 B.N2 C.CO D.O2?
Last Answer : C. CO
Description : What of the following reactions demonstrates a synthesis reaction A) Mg plus H2SO4 and gt MgSO4 plus H2 B) 2NaCl and gt 2Na plus Cl2 C) C plus O2 and gt CO2 D) Zn plus 2HCl and gt ZnCl2 plus H2?
Last Answer : C+O2 →CO2
Description : Which gas is used for converting vegetable oils into saturated fats? (1) H2 (2) O2 (3) Cl2 (4) SO2
Last Answer : (1) H2 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. ... oils are derived from polyunsaturated fatty acids (containing more than one carbon-carbon double bonds).
Description : Which of the following has the highest bond order? (1) N2 (2) O2 (3) Cl2 (4) H2
Last Answer : (1) N2 Explanation: A high bond order indicates more attraction between electrons. A higher bond order also means that the atoms are held together more tightly.
Description : Which of the following gases makes bread or cake rise making them soft and spongy? (1) CO (2) H2 (3) CO2 (4) O2
Last Answer : (3) CO2 Explanation: Breads rise due to the process of fermentation, a chemical process by which molecules such as glucose are broken down an aerobically.
Description : How H2 O2 generated in lead acid battery?
Last Answer : At end of charge, when most of the Pb is converted. H2 O2 generated from H2O. O2 appears as gas at positive plate. H2 at negative plate, i.e. gassing starts.
Description : Main constituents of purified Lurgi gas are (A) H2 , CmHn & CO2 (B) CO, H2 & CH4 (C) CO2 , O2 & CO (D) N2 , H2 & CO2
Last Answer : (B) CO, H2 & CH4
Description : L.D. converter gas (produced in steel plant) comprises mainly of (A) CO (upto 65%) & CO2 (B) CO2 & H2 (C) CO & O2 (D) CO2 & O2
Last Answer : (A) CO (upto 65%) & CO2
Description : Naphtha in a fertiliser plant is used as a source of (A) Fuel (B) H2 (C) N2 (D) O2
Last Answer : (B) H2
Description : The essential ingredient of all the synthesis gas is (A) H2 (B) O2 (C) CO2 (D) N2
Last Answer : (A) H
Description : Which of the following chemical reactions will be favoured by low pressure? (A) 2HI ⇌ H2 + I2 (B) N2O2 ⇌ 2NO2 (C) N2 + O2 ⇌ 2NO (D) None of these
Last Answer : (B) N2O2 ⇌ 2NO2
Description : LPG (Household cooking gas) is mainly a mixture of (a) Methane + Ethane (b) Acetylene + O2 (c) Butane + Isobutane (d) Acetylene + H2
Last Answer : Butane + Isobutane
Description : What products do we get on electrolysis of saturated brine using steel cathode and graphite anode in an electrolytic cell? (A) Cl2 & Na (B) Cl2 & H2 (C) O2 & H2 (D) Cl2 , H2 & NaOH solution
Last Answer : (D) Cl2 , H2 & NaOH solution
Description : In which of the following reaction equilibrium, the value of equilibrium constant Kp will be more than is Kc? (A) 2HI ⇌ H2 + I2 (B) N2O4 ⇌ 2NO2 (C) 2SO2 + O2 ⇌ 2SO3 (D) None of these
Last Answer : (B) N2O4 ⇌ 2NO2
Description : All gases during throttling process at atmospheric temperature and pressure show a cooling effect except (A) CO2 (B) H2 (C) O2 (D) N2
Description : Water gas is a mixture of (A) CO2 and O2 (B) O2 and H2 (C) H2, N2 and O2 (D) CO, N2 and H2.
Last Answer : CO, N2 and H2.
Description : The conjugate acid of water is: w) OHx) H2 y) O2 z) H3O+
Last Answer : ANSWER: Z -- H3O+
Description : Define fuel cell. Give the advantages and limitations of H2-O2 fuel cell.
Last Answer : Fuel cell: Fuel cell is an electrochemical cell which converts the chemical energy of fuel directly into the electrical energy by an electrochemical process, in which the fuel is oxidized at the anode. OR ... requires 30% of the stored energy. 7. Life span of the cells is not accurately known.
Description : Describe construction and working of H2-O2 fuel cell.
Last Answer : Construction :- )One of the simplest & most successful fuel cell is hydrogen oxygen fuel cell. ii) It consists essentially of an electrolytic solution such as 25% KOH or NaOH ... . Hydrogen & oxygen gases are bubbled through the anode & cathode compartment respectively.
Description : Which gas is used for converting vegetable oils into saturated fats ? (1) H2 (2) O2 (3) Cl2 (4) SO2
Description : The top atmosphere of the Earth directly reflects back into space nearly what part of the total amount of sun’s energy coming to it? A. 10% B. 20% C. 30% (Answer) D. 50%
Last Answer : C. 30% (Answer)
Description : Is the suns energy completely absorbed by the atmosphere?
Last Answer : No it is not.
Description : When the air the atmosphere is unevenly warmed by the sun's wind currents are the result?
Last Answer : energyenergy
Description : When the air in the atmosphere is unevenly warm by the suns wind currents are the results?
Last Answer : Essentially, yes: the Sun's heat createsconvection-currents.
Description : What is the part of the suns atmosphere closest to its surface?
Last Answer : Need answer
Description : When the air in the air the atmosphere is unevenly warmed by the suns wind current?
Description : Ultra violet light of Sun's radiation is prevented from reaching the earth's atmosphere by the layer of – (1) Oxygen (2) Hydrogen (3) Ozone (4) Helium
Last Answer : (3) Ozone Explanation: The ozone layer is a layer in Earth's atmosphere containing relatively high concentrations of ozone (03). The layer absorbs 97-99% of the Sun's medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth.
Description : What is the amount of radiant energy received each second over each square meter that is at right angles to the sun’s rays at the top of the atmosphere? a. 1400 J b. 6000 J c. 10000 J d. 800 J
Last Answer : 1400 J
Description : Ultra violet light of Sun’s radiation is prevented from reaching the earth’s atmosphere by the layer of (1) Oxygen (2) Hydrogen (3) Ozone (4) Helium
Last Answer : Ozone
Description : The ozone hole that has been detected lies in the atmosphere above – (1) Arctic Ocean (2) Antarctica (3) India (4) Alaska
Last Answer : (2) Antarctica Explanation: Ozone layer, that is, the layer of life-protecting ozone found at the top of the stratosphere. Ozone is formed in the earth's stratosphere and is critical to ... stratosphere and that some human-released chemicals are speeding up the breakdown of ozone in the atmosphere.
Description : The ozone hole is detected in the atmosphere, where is it located
Last Answer : above Antarctica
Description : The ozone hole that has been detected lies in the atmosphere above (1) Arctic Ocean (2) Antarctica (3) India (4) Alaska
Last Answer : Antarctica
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 : In addition to hydrogen, the other abundant element present on Sun’s surface is (1) Helium (2) Neon (3) Argon (4) Oxygen
Description : The balance of CO2 and O2 in atmosphere is due to _____. (1) Transportation (2) Photosynthesis (3) Respiration (4) Evaporation
Last Answer : (2) Photosynthesis Explanation: Photosynthesis takes in the carbon dioxide produced by all breathing organisms and reintroduces oxygen into the atmosphere.
Description : In order to maintain a reducing atmosphere in a furnace, it should have (A) No O2 in flue gas (B) CO in flue gas (C) High excess air (D) None of these
Last Answer : (B) CO in flue gas
Description : Which gas of the atmosphere holds up ultraviolet rays ? a) O2 b) O2 c) N2 d) CO2.
Last Answer : b) O2
Description : What percentage of the earth's atmosphere does O2 comprise? w) 75% x) 50% y) 21% z) 32%
Last Answer : ANSWER: Y -- 21%
Description : The radioactive element most commonly detected in humans is: w) potassium-40 x) cobalt-60 y) iodine-131 z) plutonium-238
Last Answer : ANSWER: W -- POTASSIUM-40
Description : Green house gases blanket/block the infrared radiation from earth's surface to the atmosphere leading to its progressive warming up. Which of the following gases does not exhibit green house effect? (A) CO2 (B) H2 (C) SO3 (D) N2
Last Answer : (C) SO3
Description : What are two tracks he suns energy follows when it reaches earth?