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During a chemical change(i) New substanc...

During a chemical change____(i) New substance is formed(ii) Heat, light, radiation or sounds may be produced(iii) New colour or smell may appear(iv) It is a temporary change

A

I and II only

B

I II and IV only

C

i,iiand iii only

D

All of these

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In which change new substance is formed.?

Statement (i) : A physical change is one in which the substance under going change is not destroyed and no new substance is formed.Statement (ii) Glowing of an electric bulb is a physical change.Statement (iii) : When antacid tablet is dropped in water, it fizzes. This is a chemical change.

Chemical reactions are invariably associated with the transfer of energy either in the form of hear or light. In the laboratory, heat changes in physical and chemical processes are measured with an instrument called calorimeter. Heat change in the process is calculated as: q= ms Delta T , s= Specific heat = c Delta T = Heat capacity. Heat of reaction at constant pressure is measured using simple or water calorimeter. Q_(v)= Delta U = Internal energy change, Q_(P) = DeltaH, Q_(P) = Q_(V) + P Delta V and DeltaH = Delta U+ Delta nRT . The amount of energy released during a chemical change depends on the physical state of reactants and products, the condition of pressure, temperature and volume at which the reaction is carried out. The variation of heat of reaction with temperature and pressure is given by Kirchoff's equation: (DeltaH_(2) - DeltaH_(1))/(T_(2)-T_(1))= Delta C_(P) (At constant pressure), (DeltaU_(2) - DeltaU_(1))/(T_(2)-T_(1)) = DeltaC_(V) (At constant volume) The enthalpy change (DeltaH) for the reaction N_(2) (g) + 3H_(2)(g) rarr 2NH_(3)(g) is -92.38kJ at 298 K. The internal energy change DeltaU at 298 K is

Chemical reactions are invariably associated with the transfer of energy either in the form of hear or light. In the laboratory, heat changes in physical and chemical processes are measured with an instrument called calorimeter. Heat change in the process is calculated as: q= ms Delta T , s= Specific heat = c Delta T = Heat capacity. Heat of reaction at constant pressure is measured using simple or water calorimeter. Q_(v)= Delta U = Internal energy change, Q_(P) = DeltaH, Q_(P) = Q_(V) + P Delta V and DeltaH = Delta U+ Delta nRT . The amount of energy released during a chemical change depends on the physical state of reactants and products, the condition of pressure, temperature and volume at which the reaction is carried out. The variation of heat of reaction with temperature and pressure is given by Kirchoff's equation: (DeltaH_(2) - DeltaH_(1))/(T_(2)-T_(1))= Delta C_(P) (At constant pressure), (DeltaU_(2) - DeltaU_(1))/(T_(2)-T_(1)) = DeltaC_(V) (At constant volume) The specific heat of I_(2) in vapoour and solid state are 0.031 and 0.055 cal/g respectively. The heat of sublimation of iodine at 200^(@)C is 6.096 kcal mol^(-1) . The heat of sublimation of iodine at 250^(0)C will be

Chemical reactions are invariably assocated with the transfer of energy either in the form of heat or light. In the laboratory, heat changes in physical and chemical processes are measured with an instrument called calorimeter. Heat change in the process is calculated as: q= ms DeltaT , s= specific heat = c Delta T , c= heat capacity Heat of reaction at constant volume is measured using bomb calorimeter. qv= Delta U= internal energy change. Heat of reaction at constant pressure is measured using simple or water calorimeter. q_(p) = Delta H, q_(p) = q_(v) + P Delta V, DeltaH = DeltaU + Delta nRT The amount of energy released during a chemical change depnds on the physical state of reactants and products, the condition of pressure, temperature and volume at which the reaction is carried out. The variation of heat of reaction with temperature and pressure is given by Kirchhoff's equation: (DeltaH_(2)- DeltaH_(1))/(TT_(2)-T_(1)) = DeltaC_(P) (At constant pressure), (DeltaU_(2)- DeltaU_(1))/(TT_(2)-T_(1)) = DeltaC_(V) (At constant volume) The heat capacity of bomb calorimeter (with its contents) is 500J/K. When 0.1g of CH_(4) was burnt in this calorimeter the temperature rose by 2^(@)C . The value of DeltaU per mole will be

Chemical reactions are invariably assocated with the transfer of energy either in the form of heat or light. In the laboratory, heat changes in physical and chemical processes are measured with an instrument called calorimeter. Heat change in the process is calculated as: q= ms DeltaT , s= specific heat = c Delta T , c= heat capacity Heat of reaction at constant volume is measured using bomb calorimeter. qv= Delta U= internal energy change. Heat of reaction at constant pressure is measured using simple or water calorimeter. q_(p) = Delta H, q_(p) = q_(v) + P Delta V, DeltaH = DeltaU + Delta nRT The amount of energy released during a chemical change depnds on the physical state of reactants and products, the condition of pressure, temperature and volume at which the reaction is carried out. The variation of heat of reaction with temperature and pressure is given by Kirchhoff's equation: (DeltaH_(2)- DeltaH_(1))/(TT_(2)-T_(1)) = DeltaC_(P) (At constant pressure), (DeltaU_(2)- DeltaU_(1))/(TT_(2)-T_(1)) = DeltaC_(V) (At constant volume) DeltaC_(P) for a reaction is given by 0.2T cal/deg. Its enthalpy of reaction at 10K is -14.2 kcal. Its enthalpy of reaction at 100K in kcal will be

Brown coloured metal powder is changed into black colour on heating. That metal powder may be …………… powder.

A light-yellow colour substance (some quantity) on a watch glass light. It changes into gray colour substance. What is the light-yellow colour substance? What is the gray colour substance?Which type of chemical reaction it is? Write the chemical equation for the reaction

Rearrange the following sentences in a correct order (i)You observe bubbles coming out with a hissing sound. Pass this gas through freshly prepared lime water(ii)Carbondioxide and Calcium Carbonate are formed. Hence it is a chemical change(iii)Take a tea spoon of vinegar in a test tube and odd a pinch of baking soda to it(iv)Lime water changes to milky white showing that the gas sent into the test tube is carbondioxide

NCERT TELUGU-CHANGS AROUND US-EXERCISE
  1. The process of separating soluble solid from the solution by heating o...

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  2. The gas liberated when wood is burnt is

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  3. During a chemical change(i) New substance is formed(ii) Heat, light, r...

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  4. Which of the following metal doesnot react with oxygen

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  5. Which of the following is a chemical change

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  6. Which of the following substances show chemical change on heating

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  7. change may be reversed by reversing the experiment conditions.

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  8. Statement A : The change which can be reversed to get the original sta...

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  9. Statement A : The change in which if there is a change in shape,size, ...

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  10. When carbondioxide gas is passed through lime water, the following cha...

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  11. The metal that burns with a dazzling light when burnt in oxygen:

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  12. The gas liberated when venegar is added to baking soda is

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  13. When an iron nail is immersed in copper sulphate solution, the colour ...

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  14. When carbondioxide gas is passed through lime water, the following cha...

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  15. when iren nail is dipped in glass container containg coppur sulphate a...

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  16. Carbondioxide turns lime water into milky white due to the formation o...

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  17. Rearrange the following sentences in a correct order (i)You observe bu...

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  18. In galvanization process, iron is coated withmetal

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  19. Which of the following gas turns lime water to milky

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  20. The metal which is burning with dazzling light as shown in the

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