Description : Is Melting coin being heated and turn black this is used as a test for metal a chemical or a physical change?
Last Answer : hg
Description : For a substance, density, solubility and melting point are examples of: w) physical properties x) amorphous properties y) chemical properties z) potential properties
Last Answer : ANSWER: W -- PHYSICAL PROPERTIES
Description : What are the changes in the kinetic energy as a substance is heated to its melting point?
Last Answer : The kinetic energy increase.
Description : Is butter melting on warm toast physical or chemical change?
Last Answer : What is the answer ?
Description : Is ice cream melting a chemical change or a physical change?
Last Answer : Melting ice cream is a physical change because it has the ability to go back to it's frozen form and be ice cream again. The chemical identity of it isn't changed.
Description : The filament of an electric lamp becomes white hot but the lead-in wires holding the filament are only slightly heated because they (a) have smaller current passing through them (b) have very low resistance (c) have higher melting point (d) are made of black iron
Last Answer : Ans:(b)
Description : Physical change of a solid to a liquid at the melting point?
Last Answer : This is the transformation of a solid in a liquid (melting).
Description : Is melting salt a chemical reaction or physical reaction?
Last Answer : Need answer
Description : Is Snow melting is a physical or chemical?
Last Answer : It is a Physical Change. Melting it does not change whatcomponents/elements are found in snow. It is just a phase changefrom solid to liquid.
Description : Why is melting wax a physical properties of flammability is a chemical property?
Last Answer : Melting is a physical property because the chemical composition remain unchanged.Flammability is a chemical property because involve a combustion reaction.
Description : What is Burning sugar for caramel is a physical change or a chemical change?
Description : Is boiling sugar to make caramel a physical change or chemical?
Last Answer : Physical
Description : (a) What happens when a Ferromagnetic or Ferrimagnetic solid is heated ? (b) The ions of MgO and NaF all have the same number of electrons and intermolecular distance are about the same (235 & 215 pm). Why are the melting points are so different (2642 °C & 992 °C ?
Last Answer : (a) It changes into paramagnetic at hight temperature due to randomization of spins. (b) The ions in MgO carry two unit charges. In NaCl only one unit charge. Hence electrostatic forces of attraction in MgO are stronger.
Description : What is the melting point of sugar ?
Last Answer : The melting point of sugar is 160 degrees.
Description : How could you use the physical properties of melting and boiling point to identify a substance?
Last Answer : The melting point and boiling point of a pure substance are veryspecific numbers; knowing these allows you to narrow down thepossible identity of the substance.
Description : Consider (R)- and (S)-2-butanol. Which physical property distinguishes the two compounds? (a) melting point (b) solubility in common solvents (c) Rotation of plane-polarized light (d) Infrared spectrum
Last Answer : Rotation of plane-polarized light
Description : One of the most common physical tests performed on fats is a determination of the ____ point. a. boiling c. melting b. cooling d. separating
Last Answer : c. melting
Description : Refractory metals are known for which of the following properties: w) lack of chemical reactivity x) low density y) high melting point z) high thermal conductivity
Last Answer : ANSWER: Y -- HIGH MELTING POINT
Description : Which products will be obtained when lead nitrate is heated simply. Write balanced chemical equation for the reaction? State the type of chemical reaction that occur in the change. -Chemistry
Last Answer : Answer. Lead monoxide, nitrogen dioxide and oxygen gas will be liberated. It is thermal decomposition reaction.
Description : A chemical change takes place when iron (A) Rusts (B) Melts (C) Is heated (D) None of these
Last Answer : (A) Rusts
Description : Is mixing sugar and cinnamon physical or chemical?
Last Answer : physical
Description : Melting temperature of DNA is increased by its (A) A and T content (B) G and C content (C) Sugar content (D) Phosphate content
Last Answer : Answer : B
Description : Is the sky being blue a physical or chemical change?
Last Answer : Neither.
Description : The sticky substance formed when sugar is heated to about 473K is called
Last Answer : caramel.
Description : Pick out the wrong statement. (A) Low intensity explosives are also called propellants, whereas high intensity explosive are called detonators (B) Gun powder comprises of 75% salt petre, 15% charcoal ... TNT is a hygroscopic explosive having very high melting point and is non-toxic to human being
Last Answer : (D) TNT is a hygroscopic explosive having very high melting point and is non-toxic to human being
Description : Water (specific heat cv= 4.2 kJ/ kg ∙ K ) is being heated by a 1500 W h eater. What is the rate of change in temperature of 1kg of the water? A. 0.043 K/s B. 0.179 K/s C. 0.357 K/s D. 1.50 K/s Formula: Q = mcv ( T)
Last Answer : 0.179 K/s
Description : What type of defect arise when a solid is heated? Which physical property is affected by it and what way ?
Last Answer : Vacancy defect is created, it is because on heating some atoms leaved the lattice site completely also the density decreases.
Description : What type of defect can arise when a solid is heated ? Which physical property is affected by this and in what way ?
Last Answer : When a solid is heated vacancy defect arises. This is because on heating some atoms or ions leacve the lattice site completely some lattice sites are vacant. As a result of this defect the density of the substance decreases, because some atoms leave the structure completely.
Description : Are freezing point and melting point same with respect to change of state ? Comment.
Last Answer : Are freezing point and melting point same with respect to change of state ? Comment.
Description : When pressure is increased the melting point of ice – (1) increases (2) does not change (3) decreases (4) depends on the impurities in the ice
Last Answer : (3) decreases Explanation: In this case. if we increase the pressure on the ice the ice-water system wants to try to lower it again. It can do that by making itself fit into a ... the melting point of ice decreases because of the inversal relationship between the pressure and melting point of ice.
Description : As the molecular weight of alkanes increases, how do the boiling point and melting point change? (a) boiling point increases ; melting point increases. (b) boiling point increases ; ... decreases (d) boiling point increases ; melting point increases sequentially for alkanes over four carbons.
Last Answer : boiling point increases ; melting point increases sequentially for alkanes over four carbons.
Description : Change in volume of metals from absolute zero temperature to their melting points is (A) Almost same for all metals (B) Different for different metals (C) Less for low melting point metals (D) Less for high melting point metals
Last Answer : (A) Almost same for all metals
Description : When pressure is increased the melting point of ice (1) increases (2) does not change (3) decreases (4) depends on the impurities in the ice
Last Answer : decreases
Description : What is conclusive evidence that mixing sugar in water is a physical change?
Description : Write chemical equation reactions taking place when carried out with the help of (a) Iron reacts with steam (b) Magnesium reacts with dil HCl (c) Copper is heated in air. -Chemistry
Last Answer : This is the Answer.
Description : 2g of ferrous sulphate crystals are heated in a dry boiling tube. (i) List any two observations. (ii) Name the type of chemical reaction taking place. (iii) ‘Write the chemical equation for the reaction. -Chemistry
Last Answer : Answer. (i) •Green colour of Fe SO4 disappears and reddish brown solid is formed. • Smell of burning sulphur. (ii) Decomposition reaction
Description : What happens when ethanol is heated with acidified potassium dichromate solution? Write the chemical equation.
Last Answer : Answer. Ethanol is oxidised to ethanoic acid with the help of acidified K2Cr2O7. CH3CH2OH + 2O → CH3COOH + H2O
Description : Melting of ice exemplifies a/an (A) Adiabatic process (B) Endothermic reaction (C) Exothermic reaction (D) Process involving a chemical reaction
Last Answer : (B) Endothermic reaction
Description : Is heating sugar to form a caramel a chemical change?
Last Answer : yes
Description : Fermentation of grapes is considered as a chemical reaction as it is a (a) chemical change (b) sugar in grapes converts into alcohol (c) Irreversible change (d) all the above
Last Answer : (d) all the above
Description : The addition of any substance to water which leads to change in its physical and chemical characteristics is defined as water pollution. It results in
Last Answer : The addition of any substance to water which leads to change in its physical and ... Increased photosynthesis D. Increased turbidity and deoxygenation
Description : What kind of combustion is observed in alkanes? Why do air holes of a gas burner have to be adjusted when vessel being heated gets blackened by the flame? -Science
Last Answer : Alkanes are saturated hydrocarbons and generally burn in air with a blue, non-sooty flame. If the bottoms of the cooking vessels in our homes are getting blackened, it shows that the air holes of the gas stove are getting blocked and the fuel is not burning completely.
Description : Why should the thermometer never touch the bottom of the container that is being heated?
Last Answer : The inner wall of the chamber is water-cooled and the heat from the particles is removed via conduction through the wall to the water and convection of the heated water to an external ... by the surrounding vacuum chamber. The neutron flux is reduced significantly at a purpose-built neutron s
Description : Glyoxal (CHOCHO) on being heated with concentrated NaOH forms
Last Answer : Glyoxal (CHOCHO) on being heated with concentrated NaOH forms
Description : Do you throw away the skin that sometimes forms on the surface of milk while it s being heated stir it back into the milk?
Last Answer : It is up to you. Some people actually scoop up the skin and either dispose of it, or even eat it (it is still milk, after all). If stirred back in, it may make the rest of the milk rather lumpy.
Description : Which would expand the most on being heated?
Last Answer : – Air
Description : A lead-acid battery cell sustaining a short circuit _______. A. will be indicated by lime accumulation on the terminal posts B. will have unusually high cell voltage C. will become excessively heated while being charged D. cannot be completely discharged under load
Last Answer : Answer: C
Last Answer : Air