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

1 Answer

Answer :

(A) Rusts

Related questions

Description : Of the following processes in nature, which one involves only a physical change A. A bird digests a worm. B. Photosynthesis occurs in a leaf. C. An earthquake causes a rockslide. D. A chunk of iron ore rusts.?

Last Answer : C: An Earthquake causes a rockslide

Description : Is rusts physical change or chemical change?

Last Answer : Its is chemical as

Description : Ice melts when heated up. But I solidify when I'm heated up. What am I? -Riddles

Last Answer : An egg.

Description : What is meant by ‘rusting’? With labelled diagrams, describe an activity to find out the conditions under which iron rusts. -Chemistry

Last Answer : When iron is exposed to air and moisture for a very long time, it gets covered with a brown flaky substance. This brown flaky substance is called rust and the process is called rusting. The ... when only oxygen was available, it shows that rusting cannot take place if only oxygen is available.

Description : When iron rusts, how is its weight? -Do You Know?

Last Answer : answer:

Description : When iron rusts, how is its weight?

Last Answer : – Increases

Description : When iron rusts, the weight (a) Increases (b) Decreases (c) Remains the same (d) First increases then decreases

Last Answer : Ans:(a)

Description : Iron rusts at the area (a) Cathodic area (b) Anodic area (c) Both cathodic and anodic areas (d) None of the above

Last Answer : Ans:(a)

Description : Iron rusts quickly in – (1) Rain water (2) Sea water (3) Distilled water (4) River water

Last Answer : (2) Sea water Explanation: Water is the enabler of fast oxidation of iron. So freshwater will also cause rust. However, salt water (sea water) is a very good conductor (lots of dissociated ions ... which causes the current to be re-versed and in effect the zinc corrodes rapidly, protecting the iron.

Description : When iron rusts, its weight – (1) decreases (2) increases (3) remains the same (4) first increases and then decreases

Last Answer : (2) increases Explanation: When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.

Description : When iron rusts, its weight : (1) decreases (2) increases (3) remains the same (4) first increases and then decreases

Last Answer : (2) increases Explanation: When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water an the metal.

Description : When iron rusts, its weight - (1) decreases (2) increases (3) Constant (4) None

Last Answer : (2) increases Explanation: Iron rust when they come into contact with water and oxygen. They rust faster in salty water or acid rain.

Description : Iron rusts quickly in

Last Answer : Sea water

Description : When Iron rusts; its weight?

Last Answer : increases

Description : When Iron rusts; its weight?

Last Answer : Increases

Description : Give reason: a) Iron exposed to air rusts quickly during rainy season.

Last Answer : a) Iron exposed to air rusts quickly during rainy season. Due to the presence of excess water vapour. b) Iron nail kept in a closed jar containing calcium chloride does not rust. As air is dry ... ) Tin is used to coat the inner walls of brass and copper utensils. To avoid corrosion or rusting.

Description : . Iron rusts quickly in

Last Answer : Sea water

Description : When iron rusts, its weight (1) decreases (2) increases (3) remains the same (4) first increases and then decreases

Last Answer : increases

Description : Iron rusts quickly in (1) Rain water (2) Sea water (3) Distilled water (4) River water

Last Answer : Sea water

Description : Is the body of a trucks rusts a physical or a chemical property?

Last Answer : Feel Free to Answer

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 : In case of __________ boiling, the liquid temperature is below the saturation temperature and the boiling takes place in the vicinity of the heated surface. (A) Nucleate (B) Local (C) Pool (D) Saturated

Last Answer : (B) Local

Description : after atoms and molecules of gases and liquids are heated they move away from the heat . what takes their place?

Last Answer : ions

Description : . At the Melting Moments, an ice cream parlour, customers place their orders, watch their ice- cream sundaes being prepared, and then quickly eat the sundaes in the store before the ice cream ... known as A. Inseparability B. Intangibility C. Heterogeneity D. Perishability E. Dependency

Last Answer : D. Perishability

Description : Often held but never touched, always wet but never rusts, often bites but seldom bit, to use me well you must have wit.What am I? -Riddles

Last Answer : Your tongue.

Description : What rusts metal?

Last Answer : Oxygen is a corrosive element that rusts metal.

Description : Silencing of mRNA has been used in producing transgenic plants resistant to (a) boll worms (b) nematodes (c) white rusts (d) bacterial blights.

Last Answer : (b) nematodes

Description : When ice melts into water, which type of change occurs in entropy? -Do You Know?

Last Answer : physical change ouccers

Description : What kind of change is it that some part of the wax melts in the heat when the candle is lit ?

Last Answer : When a candle is lit, some part of the wax melts in the heat. This is a physical change.

Description : What is the energy temperature and mass change when an ice cube melts?

Last Answer : The mass remain unchanged; the enthalpy of fusion is 333,55 J/g.

Description : If ice floating on water in a vessel melts, the water level in the vessel - (1) increases (2) does not change (3) first increases before decreasing (4) decreases

Last Answer : (2) does not change Explanation: When ice floating on water in a vessel melts, the water level in the vessel does not change. This is because when floating, the ice displaces an amount of water ... that the mass of the liquid displaced by a floating object is equivalent to the mass of the object.

Description : If ice floating on water in a vessel melts, the water level in the vessel _______. (1) increases (2) does not change (3) first increases before decreasing (4) decreases

Last Answer : (2) does not change Explanation: When ice floating on water in a vessel melts, the water level in the vessel does not change. This is because when floating, the ice displaces an amount of water equal to its mass, and when melted, it becomes an amount of water equal to its mass.

Description : When ice melts into water, which type of change occurs in entropy?

Last Answer : Increases

Description : Twenty grams of ice at 0˚C melts to water at 0˚C. How much does the entropy of the 20g change in this process?  a. 30.5 J/K  b. 24.6 J/K  c. 21.3 J/K  d. 15.7 J/K

Last Answer : 24.6 J/K

Description : If ice floating on water in a vessel melts, the water level in the vessel _______. (1) increases (2) does not change (3) first increases before decreasing (4) decreases

Last Answer : does not change

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

Last Answer : Melting is a physical process.

Description : . The physical state in which polymers exist is (A) Melts & rubber like state (B) Amorphous glassy state (C) Partially crystalline state (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : . Sodium melts (at atmospheric pressure) at a temperature of __________ °C. (A) 58 (B) 98 (C) 348 (D) 588

Last Answer : (B) 98

Description : Entropy of the system decreases, when (A) Snow melts into water (B) A gas expands spontaneously from high pressure to low pressure (C) Water is converted into ice (D) Both (B) & (C)

Last Answer : (D) Both (B) & (C)

Description : A large iceberg melts at the base, but not at the top, because of the reason that (A) Ice at the base contains impurities which lowers its melting point (B) Due to the high pressure at the base, its melting point ... C) The iceberg remains in a warmer condition at the base (D) All (A), (B) and (C)

Last Answer : (B) Due to the high pressure at the base, its melting point reduces

Description : The atmospheric temperature during melting of ice/snow (in the atmosphere) (A) Decreases (B) Increases (C) Remain same (D) May increase or decrease; depends on the altitude where snow melts Answer

Last Answer : A) Decreases

Description : Brazing filler metal used for joining steel plates (A) Melts below the melting points of base metals (B) Melts below 300°C (C) Is copper phosphorous alloy

Last Answer : (A) Melts below the melting points of base metals

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

Description : Iron is not used alone as a catalyst in ammonia synthesis, because (A) Its activity declines rapidly, if heated to above 520°C (B) It decomposes ammonia (C) It gets oxidised above 500°C (D) None of these

Last Answer : (A) Its activity declines rapidly, if heated to above 520°C

Description : Pick out the wrong statement. Raoult's law does not apply, when the (A) Size of component molecules are not equal (B) Attractive forces between like and unlike molecules ... D) Chemical combination or molecular association between unlike molecules takes place in the formation of solution

Last Answer : (C) Component molecules are non-polar

Description : Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the ... ) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions

Last Answer : (C) The intercept of the Arrhenius plot is called the 'activation energy

Description : When an isolated thermodynamic system executes a process, (A) Work is done (B) Heat transfer takes place (C) Mass flow occurs across the boundary of the system (D) No chemical reaction takes place within the system

Last Answer : D) No chemical reaction takes place within the system