Description : When quick lime is added to water (1) heat is liberated (2) heat is absorbed (3) temperature decreases (4) no heat change takes place
Last Answer : heat is liberated
Description : Describe an activity to observe what happens when quick lime is added to water taken in a beaker. State two important observations and name the type of reaction taking place. -Chemistry
Last Answer : Answer. Aim: To observe what happens when quicklime is added to water taken in a beaker. Materials Required:- Quicklime (calcium oxide), water, beaker.Procedure: 1. Take 5 g of calcium oxide in a ... example for each of decomposion reaction carried out with help of (i) Electricity (ii) Heat (iii)
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 : What happens during seed germination? (a) Heat is liberated (b) Starch is synthesised (c) Fat is synthesised (d) Light is absorbed
Last Answer : Ans:(a)
Description : When a salt dissolves in water (a) Entropy decreases (b) Entropy increases (c) Free energy increases (d) Heat is liberated
Last Answer : Ans:(b)
Description : Excess amount of absorbed water by plants is liberated out by – (1) Evaporation (2) Osmosis (3) Diffusion (4) Transpiration
Last Answer : (4) Transpiration Explanation: Water vapour transpires constantly through pores (stomata) in the surface of plant's leaves.
Description : Excess amount of absorbed water by plants is liberated out by : (1) Evaporation (2) Osmosis (3) Diffusion (4) Transpiration
Last Answer : Transpiration
Description : Which one among the following substances evolved heat when dissolved in water? (1) Glucose (2) Fructose (3) Quick lime (4) Salt peter
Last Answer : (3) Quick lime Explanation: Quicklime is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. When limestone is heated, at about 1000° C it undergoes thermal decomposition.
Description : Very often, the farmers add lime to the soil before ploughing because (a) high concentration of lime aids the plant growth (b) lime takes up the extra moisture of the soil (c) the soil becomes soft and it becomes easy to plough (d) lime decreases the acidity of the soil
Last Answer : Ans:(d)
Description : (a) Write the essential condition for the following reaction to take place: 2AgBr--> 2Ag + Br2 Write one application of this reaction. (b) Complete the following chemical equation of a chemical ... science-5 (c) What happens when water is added to quick line. Write chemical equation. -Chemistry
Last Answer : Answer. This reaction is used in photography. (c) Slaked lime is formed with hissing sound and lot of heat is envolved.
Description : To a 25 mL `H_(2)O_(2)` solution excess acidified solution of Kl was added. The iodine liberated 20 ml of 0.3 N sodium thiosulphate solution. Use thes
Last Answer : To a 25 mL `H_(2)O_(2)` solution excess acidified solution of Kl was added. The iodine liberated 20 ml of ... strength of `H_(2)O_(2)` is 1.344 L
Description : Presence of nitrogen in combustion air does not reduce the (A) Amount of heat liberated (B) Flame temperature (C) Flue gas temperature (D) Any of the above
Last Answer : (A) Amount of heat liberated
Description : When lime juice is dropped on baking soda, brisk effervescence takes place because the gas evolved is - (1) Hydrogen (2) Oxygen (3) Carbon dioxide (4) All of them
Last Answer : (3) Carbon dioxide Explanation: When baking soda and lemon juice are added together, the reaction of the two is an acid-based reaction because it involves an acid (citric acid in the lemon juice) ... , more commonly known as baking soda). Carbon dioxide, a gas, is produced by the reaction.
Description : When lime juice is dropped on baking soda, brisk effervescence takes place because the gas evolved is (1) Hydrogen (2) Oxygen (3) Carbon dioxide (4) All of them
Last Answer : Carbon dioxide
Description : Mortar is a mixture of water sand and (1) Slaked lime (2) Quick lime (3) Limestone (4) Gypsum
Last Answer : (1) Slaked lime Explanation: Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard ... Mortar can also be used to fix, or point, masonry when the original mortar has washed away.
Description : Mortar is a mixture of water, sand and (1) Slaked lime (2) Quick lime (3) Limestone (4) Gypsum
Last Answer : Slaked lime
Description : What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential ... decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.
Last Answer : A The reaction follows an alternative pathway of lower activation energy.
Description : Bleaching powder is prepared by passing – (1) Chlorine over slaked lime (2) Oxygen over slaked lime (3) Carbon dioxide over slaked lime (4) Chlorine over quick lirne
Last Answer : (1) Chlorine over slaked lime Explanation: Calcium hypochlorite (bleaching powder) is manufactured by the calcium process: 2Cl2 + 2Ca(OH)2 (slaked lime) Ca(OCl)2 + CaCl2 + 2H2O. Bleaching powder is actually a mixture of calcium hypochlorite and the basic chloride with some slaked lime.
Description : Cement containing excess amount of lime – (1) cracks during setting (2) becomes more strong (3) is slow setting (4) is quick setting
Last Answer : (1) cracks during setting Explanation: In cement almost entire amount of lime is present in combined state as calcium silicates and calcium aluminates. Cement containing excess amount of lime cracks during ... less amount of lime is weak in strength. Setting of cement is an exothermic process.
Description : Write few uses of quick lime.
Last Answer : (i) It is an important primary material for manufacturing cement and is the cheapest form of alkali. (ii) It is used in the manufacture of sodium carbonate from caustic soda. (iii) It is employed in the purification of sugar and in the manufacture of dye stuffs.
Description : How is Calcium oxide (quick lime), CaOPrepared?
Last Answer : It is prepared on a commercial scale by heating limestone(CaCO3) in a rotary kiln at 1070-1270K. The carbon dioxide is removed as soon as it is produced to enable the reaction to proceed to completion.
Description : Bleaching powder is prepared by passing : (1) Chlorine over slaked lime (2) Oxygen over slaked lime (3) Carbon dioxide over slaked lime (4) Chlorine over quick lirne
Last Answer : Chlorine over slaked lime
Description : Cement containing excess amount of lime (1) cracks during setting (2) becomes more strong (3) is slow setting (4) is quick setting
Last Answer : cracks during setting
Description : What happens when lime is added to water ?
Last Answer : : Adding water to lime produces heat and calcium hydroxide
Description : During photosynthesis, energy is absorbed by chlorophyll, therefore it is: (a) exothermic reaction (b) endothermic reaction (c) neither exothermic nor endothermic reaction (d) the process takes place in plants only
Last Answer : (b) endothermic reaction
Description : Which of the following activities occurs during the charging process of a lead-acid storage battery? A. The specific gravity of the acid increases. B. Both plates change chemically to lead sulfate. C. The specific gravity of the acid decreases. D. Hydrogen gas is absorbed.
Last Answer : Answer: A
Description : Under what condition, the heat evolved or absorbed in a reaction is equal to its free energy change?
Last Answer : Ans. As ΔG = ΔH – TΔS. Thus, ΔG = ΔH only when either the reaction is carried out at 0^0 K or the reaction is not accompanied by any entropy change, i.e., ΔS = 0
Description : Under what condition, the heat evolved/absorbed in a reaction is equal to its free energy change?
Last Answer : Ans. In ∆G = ∆H – T. ∆S, when reaction is carried out at 0 K or ∆S = 0, then ∆G = ∆H.
Description : (i) Under what conditions is the heat absorbed by a system is equal to the work done by the system? (ii)In a process, 802 J of heat is absorbed by a system and 294 J of work is done by the system. What is the change in internal energy for the process?
Last Answer : (i) When ∆U=0 i.e, for isothermal process q = w (ii)ΔU = q + w ΔU = 802 + (-294) =508J
Description : Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids ( ... Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary
Last Answer : (B) Molecular diffusion in solid is much faster than that in liquids
Description : Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Last Answer : Answer : c
Description : Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Last Answer : Answer : a
Description : For construction of structures under water, the type of lime used, is (A) Hydraulic lime (B) Fat lime (C) Quick lime (D) Pure lime
Last Answer : Answer: Option A
Description : The lime which contains mainly calcium oxide and slacks with water, is (A) Fat lime (B) Quick lime (C) Hydraulic lime (D) Poor lime
Last Answer : Answer: Option B
Description : Hydraulic lime is obtained by (A) Burning of lime stone (B) Burning of kankar (C) Adding water to quick lime (D) Calcination of pure clay
Description : Putty is (A) Made with finely powdered chalk and linseed oil (B) Used for fixing glass panes (C) Softened by a solution of pearl ash and quick-lime soaked in water (D) All the above
Description : Which of the following lime can set under water also a) Fat Lime b) Lean lime* c) Hydraulic line d) Quick lime
Last Answer : b) Lean lime*
Description : The relative heat absorption for successively added equal areas of boiler convection heating surfaces__________ (A) Increases (B) Decreases (C) Remain unaffected (D) First increases and then decreases
Last Answer : (B) Decreases
Description : The amount of heat liberated when one mole of `NH_(4)OH` reacts with one mole of HCl is
Last Answer : The amount of heat liberated when one mole of `NH_(4)OH` reacts with one mole of HCl is A. 13.7 ... Kcal C. Less than 13.7 Kcal D. Cannot be prodicted
Description : A chemical reaction in which heat is liberated is called
Last Answer : exothermic 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 : What is the difference between quick lime and slaked lime?
Last Answer : Quick lime is calcium oxide and slaked lime is calcium hydroxide
Description : What is Quick lime?
Last Answer : Calcium oxide
Description : When quick lime is mixed with Carbon dioxide it turns into?
Last Answer : Milky colour
Description : Slaking of lime results in the formation of (a) lime (b) quick lime (c) milk of lime (d) none of these
Last Answer : (c) milk of lime
Description : What is the common name of substance ̳X‘ (a) Slaking of lime (b) quick lime (c) both (a) and (b) (d) none of the above
Last Answer : (b) quick lime
Description : CaO is called (A) Quick lime (B) Slaked lime (C) Limestone (D) Calcite
Last Answer : (A) Quick lime
Description : Which of the following is the main constituent of the mother liquor produced in salt industry? (A) Quick lime (B) Glauber's salt (C) Salt petre (D) Bromine
Last Answer : (D) Bromine
Description : Rotary kiln is not involved in the production of (A) Cement (B) Lime from limestone (C) Slaked lime from quick lime (D) None of these
Last Answer : (C) Slaked lime from quick lime
Description : Ammonia gas can be dried by (A) PCl5 (B) Quick lime (C) CaCl2 (D) Concentrated H2SO4
Last Answer : (B) Quick lime