Description : What substance changes from liquid to a solid?
Last Answer : One example is when water (liquid) is frozen and is turned into a solid (ice).
Description : Any substance above its critical temperature exists as (A) Saturated vapour (B) Solid (C) Gas (D) Liquid
Last Answer : (C) Gas
Description : Solid and liquid phases of a substance are in equilibrium at the (A) Critical temperature (B) Melting point (C) Freezing point (D) Both (B) and (C)
Last Answer : D) Both (B) and (C)
Description : What term refers to the heat needed to change a unit mass of a substance at its melting temperature from a solid into a liquid?
Last Answer : ANSWER: HEAT OF FUSION or LATENT HEAT OF FUSION or ENTHALPY OF FUSION
Description : The critical temperature is the temperature: w) above which a substance cannot be vaporized x) at which the density is a minimum y) at which solid, liquid, and vapor are in equilibrium z) above which the substance cannot be liquified.
Last Answer : ANSWER: Z -- ABOVE WHICH THE SUBSTANCE CANNOT BE LIQUIFIED.
Description : Melting temperature of DNA is the temperature at which (A) Solid DNA becomes liquid (B) Liquid DNA evaporates (C) DNA changes from double helix into supercoiled DNA (D) Native double helical DNA is denatured
Last Answer : Answer : D
Description : Shrinkage allowance on pattern is provided to compensate for shrinkage when the (A) Metal changes from liquid state to solid state at freezing temperature (B) Solid phase temperature drops ... to room temperature (D) Liquid metal temperature drops from pouring temperature to freezing temperature
Last Answer : (B) Solid phase temperature drops from freezing temperature to the room temperature
Description : The point at which the solid, liquid and gaseous forms of a substance co-exist is called its (a) boiling point (b) melting point (c) triple point (d) freezing point
Last Answer : Ans:(c)
Description : The point at which the solid, liquid and gaseous forms of a substance co-exist is called its (a) Boiling point (b) Melting point (c) Triple point (d) Freezing point
Description : Which substance is found in nature in solid , liquid , gaseous state ?
Last Answer : Water is hard , liquid , gaseous in nature.
Description : What will determine if the substance is a solid liquid or gas at 100 degrees?
Last Answer : What is the answer ?
Description : (4) Water drops in a dispersion medium of air Explanation: A colloid is a substance microscopically dispersed evenly throughout another substance. A colloidal system consists of two separate phases: a dispersed ... or gas. Cloud is a colloidal dispersion of Water drops in a dispersion medium of air.
Last Answer : Conduction band electrons have more mobility than holes because they – (1) are lighter (2) experience collision less frequently (3) have negative charge (4) need less energy to move them
Description : (2) Fat is dispersed in water Explanation: A colloid is a substance microscopically dispersed evenly throughout another substance. A colloidal system consists of two separate phases: a dispersed ... Milk is an emulsified colloid of liquid butterfat globules dispersed within a water-based solution.
Last Answer : The presence of ozone in the stratosphere is responsible for – (1) increasing the average global temperature in recent years (2) higher rate of photosynthesis (3) checking the penetration of ultra-violet rays to the earth (4) supplying oxygen for people travelling in jets
Description : The substance which does not expand on going from liquid state to solid state is – (1) Water (2) Cast-iron (3) Aluminium (4) Type metal
Last Answer : (4) Type metal Explanation: In printing, type metal (sometimes called hot metal) refers to the metal alloys used in traditional type founding and hot metal typesetting. Lead is the main constituent of ... and solidifies in a simple manner at a specific temperature. This is not the case with alloys.
Description : _________ is the transition of a given substance from the solid to the gas phase with no intermediate liquid stage. a. Convection b. Conduction c. Radiation d. Sublimation
Last Answer : Sublimation
Description : The pressure of the vapor phase of a substance that is in equilibrium with the liquid or solid phase. a. Phase Pressure b. Equilibrium Vapor Pressure c. Specific Pressure d. Equilibrium Phase Pressure
Last Answer : Equilibrium Vapor Pressure
Description : What is defined as the direct conversion of a substance from the solid to the vapor state or vice versa without passing the liquid state? A. Condensation B. Vaporization C. Sublimation D. Cryogenation
Description : What is the amount of heat needed to turn 1 kg of the substance at its melting point from the solid to liquid state? A. Heat of fusion B. Heat of vaporation C. Heat of condensation D. Heat of fission
Last Answer : Heat of fusion
Description : Which one of the following best defines the word allotropes ? A Different structural forms of an element B A pair of substances that differ by H+ C Elements that possess properties intermediate between ... a specific number of neutrons E The different phases (solid, liquid or gas) of a substance
Last Answer : A Different structural forms of an element
Description : The substance which does not expand on going from liquid state to solid state is (1) Water (2) Cast-iron (3) Aluminium(4) Type metal
Last Answer : Type metal
Description : What is the point at which matter changes from a solid in a liquid?
Last Answer : This is the melting point.
Description : In soldering, what alloy changes directly from a solid state to a liquid state?
Last Answer : Eutectic.
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 : When a solid melts, a. the temperature of the substance increases. b. the temperature of the substance decreases. c. heat leaves the substance. d. heat enters the substance.
Last Answer : heat enters the substance.
Description : The change in physical size of a substance when its temperature changes. a. intensive property b. extensive property c. volume expansion d. thermal expansion
Last Answer : thermal expansion
Description : What refers to the pressure at which a pure substance changes phase at a given temperature? A. Equilibrium pressure B. Saturation pressure C. Superheated pressure D. Subcooled pressure
Last Answer : Saturation pressure
Description : What refers to the temperature at which a pure substance changes phase at a given pressure? A. Equilibrium temperature B. Saturation temperature C. Superheated temperature D. Subcooled temperature
Last Answer : Saturation temperature
Description : Moisture in a substance exerting an equilibrium vapour pressure less than that of pure liquid at the same temperature is called the __________ moisture. (A) Bound (B) Unbound (C) Critical (D) None of these
Last Answer : (A) Bound
Description : Moisture in a solid exerting an equilibrium vapour pressure equal to that of the pure liquid at the same temperature is called the __________ moisture. (A) Unbound (B) Critical (C) Free (D) Bound
Last Answer : (A) Unbound
Description : Mixture of liquid and steam of the same substance in which both are at saturation temperature. a. dry steam b. current steam c. wet steam d. aerosol
Last Answer : wet steam
Description : Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid ... pressure at temperature above 430° C. (4) It is a thermo chemical decomposition of organic waste
Last Answer : (2) The process occurs at a temperature above 430°C at atmospheric pressure. Explanation: Pyrolysis is a thermo-chemical decomposition of organic material at elevated temperatures in the ... . Pyrolysis generally takes place well above atmospheric pressure at temperatures exceeding above 430 °C.
Description : Metals can be _____ at room temperature. (1) Liquid only (2) Solid only (3) Solid or liquid (4) Solid, liquid or gas
Last Answer : (3) Solid or liquid Explanation: All metals except Mercury are solid at room temperature. Mercury is the only metallic element that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is bromine.
Description : The absolute zero is a temperature at which ______. (1) molecular motion in a gas would cease (2) water freezes (3) all gases become liquid (4) all gases become solid
Last Answer : (1) molecular motion in a gas would cease Explanation: Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance.
Last Answer : (1) molecular motion in a gas would cease Explanation: Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. It is the point at which all motion in matter stops.
Description : The absolute zero is a temperature at which - (1) Molecular motion in a gas would cease (2) Water freezes (3) All gases become liquid (4) All gases become solid
Last Answer : (1) Molecular motion in a gas would cease Explanation: Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Description : Pick out the correct statement. (A) Plastics are good conductors of heat and electricity (B) All the polymers are highly crystalline in nature (C) Polymers can be vaporised by heating to ... D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
Last Answer : (D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation
Description : If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution ... On heating, a vapor phase will appear; while on cooling, a solid phase will appear
Last Answer : (D) On heating, a vapor phase will appear; while on cooling, a solid phase will appear
Description : Predict the entropy change in- (i) A liquid crystallizes into solid (ii) Temperature of a crystalline solid raised from 0K to 115K.
Last Answer : Ans. (i) Entropy decreases because molecules attain an ordered state. (ii) Entropy increases because from 0K to 115K average kinetic of moleculesincreases.
Description : Bound moisture is that liquid which exerts an equilibrium vapor pressure __________ that of the pure liquid at the given temperature. (A) Less than (B) More than (C) Equal to (D) Either (A) or (B); depends on the solid
Last Answer : (A) Less than
Description : Explain why o-hydroxybenzaldehyde is a liquid at room temperature while p-hydroxybenzaldehyde is a high melting solid.
Last Answer : Due to interamolecular H-bonding ortho-hydroxy benzaldehyde exists as discrete molecule whereas due to intermolecular H-bonding, p-hydroxybenzaldehyde exists as associated molecules. To break these intermolecular ... a liquid at room temperature while p-hydroxy benzaldehyde is a high melting solid.
Description : Which of the following psychrometric processes is followed by water vapour laden unsaturated air, when it is passed through solid or liquid adsorbent? (A) Cooling and dehumidification ... (C) Dehumidification with dry bulb temperature remaining constant (D) None of these
Last Answer : (B) Heating and dehumidification at almost constant wet bulb temperature
Description : Which of the following is the most controlling factor for the rate of bubble detachment from the hot solid surface? (A) Liquid density (B) Liquid viscosity (C) Hot surface temperature (D) Interfacial tension
Last Answer : (D) Interfacial tension
Description : Heat transfer rate to the charge/stock in a furnace does not depend upon the (A) Type of fuels viz. solid, liquid or gaseous (B) Flue gas temperature (C) Emissivity of refractory walls (D) Initial temperature of the charged stock
Last Answer : (A) Type of fuels viz. solid, liquid or gaseous
Description : The optimum percentage of excess air for combustion depends upon the__________ of the fuel. (A) Type (solid, liquid or gaseous) (B) Calorific value (C) Sulphur content (D) Ignition temperature
Last Answer : (A) Type (solid, liquid or gaseous)
Description : A liquid would wet the solid, if adhesion forces as compared to cohesion forces are (A) Less (B) More (C) Equal (D) Less at low temperature and more at high temperature
Last Answer : Answer: Option B
Description : What is the name of the temperature and pressure conditions at which water can be in the solid, liquid and gas phases simultaneously?
Last Answer : ANSWER: TRIPLE POINT
Description : What is the name given to the temperature and pressure at which solid, liquid, and gas coexist for a pure material?