Description : The Classical example of redox reaction is Combustion of fossil fuel. During combustion of fossil fuels, the carbon compound in the fossil fuel reacts with oxygen in the presence of a heat source to ... to react with oxygen, so the energy used in portion of combustion is an endothermic reaction.
Last Answer : Combustion of fossil fuel
Description : If a hydrocarbon reacts with a diatomic molecule of oxygen would it be a combustion, synthesis, or single or double replacement reaction?
Last Answer : answer:Say the two are isolated in a certain area and it’s hot enough to get them to collide. I think you’d get HCO2. So synthesis. And I’ve read that HCO2 has to do with, “The Lewis Structure.” I’d try e-mailing a chemistry, physics or an astronomy professor if I were you.
Description : An unknown substance (P) functions as weak base in water. It produces silver mirror test. It reacts with dilute `HCl` to produce (Q) which turns blue
Last Answer : An unknown substance (P) functions as weak base in water. It produces silver mirror test. It reacts with dilute `HCl` ... ` C. `NH_(2)OH` D. `HPO_(3)`
Description : What is the substance that reacts with hydrochloric acid to produce chlorine gas?
Last Answer : This compound is the manganese dioxide, MnO2.
Description : For the irreversible reaction, Ca+ 2C = Ca C2, Δ H°298 = - 60000 J . mole-1. If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved ... will be (A) 30,000 J (B) 60,000 J (C) 90,000 J (D) 2,40,000 J
Last Answer : (C) 90,000 J
Description : An organic compound contain 69% carbon and 4.8% hydrogen, the remaining being oxygen. Calculate the masses of carbon dioxide and water produced when 0.20g of this substance is subjected to complete combustion.
Last Answer : Calculation of mass of CO2 produced: Mass of compound =0.20g %C =12 x C 69=12*mass of CO2 formed*100/44*0.2 Mass of CO2 formed =69*44*.2/12*100 = 0.506g Similarly, % H =2* mass of H2Oformed*100/18* ... compound 4.8=2* mass of H2Oformed*100/18* 0.2 Mass of H2Oformed =4.8*18*0.2/2*100 =0.0864g
Description : A substance which reacts with oxygen giving heat is called a combustible substance. Which one of the following is a combustible substance? a) iron nail b)glass c)stone piece d)wood
Last Answer : d)wood
Description : "The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances". This is the (A) Lewis- ... (B) Statement of Van't Hoff Equation (C) Le-Chatelier's principle (D) None of these
Last Answer : (D) None of these
Description : Fuel' can be defined as a substance which produces heat by (A) Combustion (B) Nuclear fission (C) Nuclear fusion (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C
Description : Infection of Ascaris usually occurs by (a) Tse-tse fly (b) mosquito bite (c) drinking water containing eggs of Ascaris (d) eating imperfectly cooked pork
Last Answer : (c) drinking water containing eggs of Ascaris
Description : Combustion of an alkene with sufficient oxygen will produce (a) carbon dioxide and water (b) carbon monoxide and water (c) only carbon dioxide (d) only carbon monoxide
Last Answer : carbon dioxide and water
Description : What is the reaction when solid manganese dioxide reacts with hydrochloric acid to produce manganese chloride liquid water and chlorine gas?
Last Answer : The chemical reaction is:MnO2 + 4 HCl = MnCl2 + Cl2 + 2 H2O
Description : Pick out the wrong statement. (A) Enthalpies of all elements in their standard states are assumed to be zero (B) Combustion reactions are never endothermic in nature (C) Heat of reaction ... to the change in internal energy (D) Clausius-Clapeyron equation is not applicable to melting process
Last Answer : (D) Clausius-Clapeyron equation is not applicable to melting process
Description : Benzene reacts with H2 at 150°C at 30 atm in the presence of Ni catalyst to give (a) Cyclohexane (b) Cyclohexene (c) n-Hexane (d) No reaction occurs
Last Answer : Cyclohexane
Description : (2) brown bottles stops the passage of light through it Explanation: Silver Nitrate is stored in dark bottles in a laboratory to prevent chemical reactions as it is sensitive to light. It reacts to light to produce silver metal.
Last Answer : In upper layer of atmosphere ozone is formed by - (1) the action of ultraviolet rays on oxygen (2) the combination of oxygen molecules (3) subjecting oxygen to high pressure (4) the action of nitrogen on oxygen in atmosphere
Description : Is the correct equation for the reaction below. One molecule of propane gas reacts with five molecules of oxygen gas to form three molecules of carbon-dioxide gas and four molecules of water vapor?
Last Answer : Yes, it is correct.C3H8 + 5 O2 = 3 CO2 + 4 H2O
Description : Silver acetate reacts with Br2 to form methyl bromide, carbon dioxide, and AgBr. This is an example of (a) Wurtz reaction (b) Etard's reaction (c) Hunsdiecker reaction (d) Perkin reaction
Last Answer : Hunsdiecker reaction
Description : (1) the action of ultraviolet rays on oxygen Explanation: The majority of tropospheric ozone formation occurs when nitrogen oxides (NOx), carbon monoxide (CO ) and volatile organic compounds (VOCs), such as xylene, ... violet rays. NOx, CO, and VOCs are called ozone precursors. CO + 2O2 + CO2 + O3
Last Answer : Water is not effective in extinguishing a fire caused by petrol because - (1) the flame is too hot for water to cool it down (2) water and petrol react chemically (3) water and petrol are ... (4) water and petrol are immiscible with each other and petrol which forms the upper layer continues to burn
Description : Quick lime (A) Generates heat when added to water (B) Reacts with carbon dioxide (C) May be used for white-washing (D) All the above
Last Answer : Answer: Option D
Description : Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to ... tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side
Last Answer : (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger
Description : when a carbonate reacts with an acid,it produces carbon dioxide gas. how can this reaction be used in our dairy life -Biology
Last Answer : answer:
Description : The heat of combustion of carbon and monoxide are -394 and -285 KJ `mol^(-1)` respectively. The heat of formation of CO in KJ `mol^(-1)` is :-
Last Answer : The heat of combustion of carbon and monoxide are -394 and -285 KJ `mol^(-1)` respectively. The heat of formation ... B. `-109` C. `+218` D. `-218`
Description : Unreacted core model' represents the reaction involving (A) Combustion of coal particles (B) Roasting of sulphide ores (C) Manufacture of carbon disulphide from elements (D) None of these
Last Answer : (B) Roasting of sulphide ores
Description : __________ resistance is not involved in the combustion of a carbon particle. (A) Gas film (B) Ash (C) Chemical reaction (D) None of these
Last Answer : (B) Ash
Description : Scavenging air in diesel engine means a. air used for combustion under pressure b. forced air for cooling the cylinder c. burnt air containing products of combustion d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke
Last Answer : ANSWER d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke
Description : Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. (A) 80 (B) 130 (C) 180 (D) 250
Last Answer : (B) 130
Description : Producer gas containing least amount of tar is produced by the (A) Partial combustion of coal (B) Partial combustion of large size (< 50 mm) coke (C) High pressure gasification of coal (e.g. in Lurgi gasifier) (D) Atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier)
Last Answer : (B) Partial combustion of large size (< 50 mm) coke
Description : A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2 . It means that (A) 21% excess air has been used for combustion (B) 21% excess oxygen has ... (C) Complete combustion of fuel has taken place (D) No excess air has been used for combustion
Last Answer : (C) Complete combustion of fuel has taken place
Description : Which of the following would require least amount of secondary air for combustion? (A) Coke breeze containing 25% ash and 2% volatile matter (B) Anthracite containing 10% volatile matter and 8% ash ... ash and 25% volatile matter (D) Semi-bituminous coal containing 25% ash and 20% volatile matter
Last Answer : (A) Coke breeze containing 25% ash and 2% volatile matter
Description : Assertion (A): For a particular reaction, heat of combustion at constant pressure `(q_(P))` is always greater than that at constant volume `(q_(V))`.
Last Answer : Assertion (A): For a particular reaction, heat of combustion at constant pressure `(q_(P))` is ... False. D. If both Assertion & Reason are false.
Description : In which step of the four-stroke engine cycle does the heat from the combustion reaction causes the pistons to move?
Last Answer : combustion and expansion
Description : Change of heat content when one mole of compound is burnt in oxygen at constant pressure is called the (A) Calorific value (B) Heat of reaction (C) Heat of combustion (D) Heat of formation
Last Answer : (C) Heat of combustion
Description : The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is (A) Full annealing (B) Bright annealing (C) Patenting (D) None of these
Last Answer : C) Patenting
Description : Pick out the wrong statement. (A) Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom (B) The heat capacity of solid inorganic substance is exactly equal to the ... isolated system (D) At absolute zero temperature, the heat capacity for many pure crystalline substances is zero
Last Answer : (C) There is an increase in entropy, when a spontaneous change occurs in an isolated system
Description : What has a form of energy that can produce heat light magnetism and electrical charges?
Last Answer : if you mean to have commas between heat, light, magnetism, andelectrical charges then there is none. if heat light magnetism isall one thing then you're on your own.
Description : In allergic reaction: a. Arthus reaction is a type IV reaction b. anaphylaxis occurs in patients who have had no previous exposure to the offending substance c. contact dermatitis is a type IV reaction d. positive Mantoux test is a type III reaction
Last Answer : contact dermatitis is a type IV reaction
Description : Heat engine deriving its power from the energy liberated by the explosion of a mixture of some hydrocarbon, in a gaseous or vaporized form. a. Dual Combustion Engine b. Internal Combustion Engine c. External Combustion Engine d. None of the above
Last Answer : Internal Combustion Engine
Description : According to first law of thermodynamics (a) mass and energy are mutually convertible (b) Carnot engine is most efficient (c) heat and work are mutually convertible (d) mass and light are mutually convertible (e) heat flows from hot substance to cold substance.
Last Answer : Answer : c
Description : Pick out the wrong statement (A) Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure substance (B) In case of gas absorption, HETP is ... reaction (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Last Answer : (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Description : The rate at which a chemical substance reacts is proportional to its (A) Active mass (B) Molecular weight (C) Equivalent weight (D) Atomic weigh
Last Answer : (A) Active mass
Description : The rate at which a chemical substance reacts is proportional to its (A) Active mass (B) Equivalent weight (C) Molecular weight (D) None of these
Description : What is the word that describes a substance that reacts with both strong acids and strong bases?
Last Answer : ANSWER: AMPHOTERIC
Description : . An irreversible aqueous phase reaction, A + B → P, is carried out in an adiabatic mixed flow reactor. A feed containing 4kmole/m3 of each A and B enters the reactor at 8m3 /hr. If the temperature of ... be assumed to be independent of temperature and composition. (A) 190 (B) 290 (C) 390 (D) 490
Last Answer : (B) 290
Description : Which of the following accounts for maximum energy loss in a boiler? (A) Flue gases (B) Ash content in the fuel (C) Incomplete combustion (D) Unburnt carbon in flue gases
Last Answer : (A) Flue gases
Description : The enthalpy combustion of a substance
Last Answer : The enthalpy combustion of a substance A. Always positive B. Always negative C. Numerically equal to the heat of formation D. 1 and 3 both
Description : _________ is a substance which undergoes spontaneous combustion. a) wood b)coal c)sodium d)cow dung cakes
Last Answer : c)sodium
Description : A mystical substance supposedly released during combustion was called: w) thermal flax x) ether y) caloric z) phlogiston (pron: flow-gis-ton)
Last Answer : ANSWER: Z -- PHLOGISTON
Description : Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of ... molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction
Last Answer : (C) A catalyst lowers the activation energy of the reacting molecules