Is Melting coin being heated and turn black this is used as a test for metal a chemical or a physical change?

Is Melting coin being heated and turn black this is used as a test for metal a chemical or a physical change?
by

1 Answer

Answer :

hg
by
selected by

Related questions

When sugar canalize on being heated above its melting point is physical change or chemical?

Description : When sugar canalize on being heated above its melting point is physical change or chemical?

Last Answer : Melting is a physical process.

Is stamping a coin a physical or chemical change?

Description : Is stamping a coin a physical or chemical change?

Last Answer : It is a physical change.

Is stamping a coin a physical or chemical change?

Description : Is stamping a coin a physical or chemical change?

Last Answer : It is a physical change.

10.(a) An ore on treatment with dilute hydrochloric acid produces brisk effervesces. What type of ore is this? What steps will be required to obtain metal from the enriched ore. , (b) Copper coin is kept immersed in silver nitrate solution for some time. What change will take place in coin and colour of the solution ? Write balanced chemical equation of the reaction involved. -Chemistry

Description : 10.(a) An ore on treatment with dilute hydrochloric acid produces brisk effervesces. What type of ore is this? What steps will be required to obtain metal from the enriched ore. , (b) ... in coin and colour of the solution ? Write balanced chemical equation of the reaction involved. -Chemistry

Last Answer : (a) Carbonate ore: (i) Calcination: Carbonate ore is heated in limited supply of air and oxide is obtained, e.g. (b) Copper, being more reactive than silver will displace silver from silver nitrate ... and there will be deposition of silver on copper coin. The colour of solution will turn to blue.

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

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)

Is butter melting on warm toast physical or chemical change?

Description : Is butter melting on warm toast physical or chemical change?

Last Answer : What is the answer ?

Is ice cream melting a chemical change or a physical change?

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.

Is melting salt a chemical reaction or physical reaction?

Description : Is melting salt a chemical reaction or physical reaction?

Last Answer : Need answer

Is Snow melting is a physical or chemical?

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.

Why is melting wax a physical properties of flammability is a chemical property?

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.

For a substance, density, solubility and melting point are examples of: w) physical properties x) amorphous properties y) chemical properties z) potential properties

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

What are the changes in the kinetic energy as a substance is heated to its melting point?

Description : What are the changes in the kinetic energy as a substance is heated to its melting point?

Last Answer : The kinetic energy increase.

(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 ?

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.

When a metal sulphate is heated in dry test tube, the colour changes from blue to white. Then metal sulphate may be :

Description : When a metal sulphate is heated in dry test tube, the colour changes from blue to white. Then metal sulphate may be :

Last Answer : When a metal sulphate is heated in dry test tube, the colour changes from blue to white. Then metal sulphate may ... . `Na_(2)SO_(4)` D. None of these

Is two clear liquids turn white when mixed togethera physical or chemical change?

Description : Is two clear liquids turn white when mixed togethera physical or chemical change?

Last Answer : Chemical.

Is two clear liquids turn white when mixed togethera physical or chemical change?

Description : Is two clear liquids turn white when mixed togethera physical or chemical change?

Last Answer : Chemical.

When Metal is drawn out into a wire is it a chemical change or physical change?

Description : When Metal is drawn out into a wire is it a chemical change or physical change?

Last Answer : Need answer

Two inorganic compounds A and B were heated in a dry test tube. A evolved a colourless gas which turned lead acetate paper black and B evolved a gas w

Description : Two inorganic compounds A and B were heated in a dry test tube. A evolved a colourless gas which turned lead acetate paper black and B evolved a gas w

Last Answer : Two inorganic compounds A and B were heated in a dry test tube. A evolved a colourless gas which turned lead acetate ... ` D. `S^(2-), NO_(3)^(-)`

Physical change of a solid to a liquid at the melting point?

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).

Is Steel rod Be heated into a molten metal is example of a phase change?

Description : Is Steel rod Be heated into a molten metal is example of a phase change?

Last Answer : Feel Free to Answer

A metal sheet with circular hole is heated. what change will be in the hole?

Description : A metal sheet with circular hole is heated. what change will be in the hole?

Last Answer : It will Expand

1. Which post does the Constitution of India does not mention? 2. What is the ‘Solar Corona’ mainly? 3. Who was a blind poet who worshipped Krishna and spread Krishna Bhakti cult? 4. A metal sheet with circular hole is heated. what change will be in the hole? 5. Which bank prints currency notes of the denomination of Rs. 100?

Description : 1. Which post does the Constitution of India does not mention? 2. What is the Solar Corona' mainly? 3. Who was a blind poet who worshipped Krishna and spread Krishna Bhakti cult? 4. A ... ? 20. By inserting a soft iron piece into solenoid, what does the strength of the magnetic field?

Last Answer : Answer : 1. The Deputy Prime Minister 2. Consists of molten lava 3. Surdas 4. It will Expand 5. The Bank Note Press, Dewas 6. Kathak 7. Hydrogen 8. Alain khan, the father of Dilawar Khan 9. ... Sarwani 14. 1991 15. 15 16. 46 gram 17. Chinook 18. Painters 19. State Election Commission 20. Increase

Is taking out your best silver spoons and know that it is very dull and it has black dots on them is it a chemical change or physical change?

Description : Is taking out your best silver spoons and know that it is very dull and it has black dots on them is it a chemical change or physical change?

Last Answer : What is the answer ?

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

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.

A chemical change takes place when iron (A) Rusts (B) Melts (C) Is heated (D) None of these

Description : A chemical change takes place when iron (A) Rusts (B) Melts (C) Is heated (D) None of these

Last Answer : (A) Rusts

Which elements are called coin metal ?

Description : Which elements are called coin metal ?

Last Answer : The elements of group 11 of the periodic table are called coin metals.

What is coin metal ?

Description : What is coin metal ?

Last Answer : Elements such as copper ( Cu), silver ( Ag) and gold ( Au) in group 11 in the periodic table have metallic properties such as luminosity. Historically, these metals have been used to make coins ... as a medium of exchange for buying and selling and other purposes. These are called coinage metals .

What is coin metal ?

Description : What is coin metal ?

Last Answer : In the periodic table, the elements like copper , silver and gold ( Au) in group-11 are called coin metals.

Is the sky being blue a physical or chemical change?

Description : Is the sky being blue a physical or chemical change?

Last Answer : Neither.

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)

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

What type of defect arise when a solid is heated? Which physical property is affected by it and what way ?

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.

What type of defect can arise when a solid is heated ? Which physical property is affected by this and in what way ?

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.

Above image shows an experiment where copper sulphate crystals are heated. When we heat the crystals, they turn white. If you moisten the crystals again with water you will find that colour of crystals reappears . (1) How many water molecules are present in one formula unit of copper sulphate (a)5 (b)2 (c)6 (d)7

Description : Above image shows an experiment where copper sulphate crystals are heated. When we heat the crystals, they turn white. If you moisten the crystals again with water you will find that colour of crystals reappears . (1 ... are present in one formula unit of copper sulphate (a)5 (b)2 (c)6 (d)7

Last Answer : (a)5

How could you use the physical properties of melting and boiling point to identify a substance?

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.

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

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

One of the most common physical tests performed on fats is a determination of the ____ point. a. boiling c. melting b. cooling d. separating

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

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

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

1.12 litre dry chlorine gas at STP was passed over a heated metal when 5.56 g of chloride of the metal was formed. What is the equivalent weight of th

Description : 1.12 litre dry chlorine gas at STP was passed over a heated metal when 5.56 g of chloride of the metal was formed. What is the equivalent weight of th

Last Answer : 1.12 litre dry chlorine gas at STP was passed over a heated metal when 5.56 g of chloride of ... formed. What is the equivalent weight of the metal ?

Which metal gives violet colour in oxidising flame when heated with borax ?

Description : Which metal gives violet colour in oxidising flame when heated with borax ?

Last Answer : Which metal gives violet colour in oxidising flame when heated with borax ? A. Fe B. Pb C. Co D. Mn

What will happen if a sheet of metal with a hole in it is heated?

Description : What will happen if a sheet of metal with a hole in it is heated?

Last Answer : Need answer

When a heated metal colls down it?

Description : When a heated metal colls down it?

Last Answer : Need answer

When a metal is heated in a flame, the electrons absorb energy and jump to higher energy state. On coming back to the lower energy state, they emit light, which we can observe in - (1) Raman spectra (2) Absorption spectra (3) Emission spectra (4) Fluorescence

Description : When a metal is heated in a flame, the electrons absorb energy and jump to higher energy state. On coming back to the lower energy state, they emit light, which we can observe in - (1) Raman spectra (2) Absorption spectra (3) Emission spectra (4) Fluorescence

Last Answer : (3) Emission spectra Explanation: When a metal atom is strongly heated, its electrons absorb the heat energy and jump to a higher energy level. When the electron returns to its original position it ... to the energy the electron has released at each stage °fits fall back to its original state.

When a ring of metal is heated what happens to its hole? (1) expands (2) contracts (3) it expands or contracts according to its diameter (4) it expands or contracts according to its coefficient of expansion

Description : When a ring of metal is heated what happens to its hole? (1) expands (2) contracts (3) it expands or contracts according to its diameter (4) it expands or contracts according to its coefficient of expansion

Last Answer : (1) expands Explanation: The hole size will increase because in expansion the size between two molecules, do not increase so when the molecules on the outer edge move outward. Due to expansion, the ... expansion is the tendency of matter to change in volume in response to a change in temperature.

A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will - (1) increase (2) decrease (3) remain unaffected (4) have its shape changed

Description : A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will - (1) increase (2) decrease (3) remain unaffected (4) have its shape changed

Last Answer : (1) increase Explanation: The metal ball can be considered to be made up of several layers of thinner ones. On heating each of these layers will increase in radius.

A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will - (1) Increase (2) decrease (3) remain unaffected (4) have its shape changed

Description : A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will - (1) Increase (2) decrease (3) remain unaffected (4) have its shape changed

Last Answer : (1) Increase Explanation: The metal ball can be considered to be made up of several layers of thinner ones. On heating each of these layers will increase in radius. As the inner most layer also increases its radius, the volume inside it i.e, the volume of the hollow portion will also increase.

A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole? (1) Increase (2) Decrease (3) Remain constant (4) Will increase first and then decrease

Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole? (1) Increase (2) Decrease (3) Remain constant (4) Will increase first and then decrease

Last Answer : (1) Increase Explanation: Assuming the disc is uniform and isotropic (the same in different directions), the hole will expand in the same ratio as the metal. It is because the thermal expansion equation ... is made out of metal. And if the circumference of the hole expands, so does the diameter.

If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated? (1) Increases (2) Decreases (3) Unchanged (4) Depends upon the metal

Description : If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated? (1) Increases (2) Decreases (3) Unchanged (4) Depends upon the metal

Last Answer : (1) Increases Explanation: When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using ... of expansions, we find that the hole radius increases at the same linear rate as the metal.

The process, whereby electrons gain sufficient energy to be released from the surface of a thin, heated metal plate, is known as _____________. A. photo electric emission B. secondary emission C. thermionic emission D. regressive emission

Description : The process, whereby electrons gain sufficient energy to be released from the surface of a thin, heated metal plate, is known as _____________. A. photo electric emission B. secondary emission C. thermionic emission D. regressive emission

Last Answer : Answer: C

A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole?

Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole?

Last Answer : Decrease

Pick out the wrong statement. (A) The toughness of a material decreases, when it is heated (B) Crane hooks are normally made of wrought iron (C) Cold working of a metal decreases its fatigue strength (D) The temperature at which new grains are formed in a metal is known as the recrystallisation temperature

Description : Pick out the wrong statement. (A) The toughness of a material decreases, when it is heated (B) Crane hooks are normally made of wrought iron (C) Cold working of a metal decreases its ... (D) The temperature at which new grains are formed in a metal is known as the recrystallisation temperature

Last Answer : (C) Cold working of a metal decreases its fatigue strength