Advertisements
Advertisements
प्रश्न
Give reason for the following:
Even though rusting is an exothermic reaction, the heat evolved when an iron nail rusts is unnoticeable.
Advertisements
उत्तर
Rusting of iron – the reaction is slow and the heat evolved is very less, hence unnoticeable.
APPEARS IN
संबंधित प्रश्न
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
How do the following help in bringing about a chemical change?
light.
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{NH3_{(g)} + HCl_{(g)} -> NH4Cl_{(s)}}\]
FILL IN THE BLANK
Positively charged ions are called ........
TRUE \ FALSE
Copper can displace iron from iron sulphate.
TRUE \ FALSE
Temperature at which a liquid starts boiling is known as the boiling point of that liquid. True or false ?
Explain by writing a word equation.
Respiration is a chemical change.
Explain by writing a word equation.
Bubbles are seen on adding lemon juice to baking soda.
Explain the term reactant and product giving examples.
State the conditions necessary for a chemical change or reaction.
Give an example of the following chemical change.
Two solids combine to form a liquid
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
What do you observe when Cl2 is passed through potassium iodide (KI) solution.
What do you observe when Cobalt chloride paper is introduced in water vapour.
Give a chemical test to distinguish between the following gases.
CO2 and SO2
Give balanced equation for the following conversion affected by heat alone on the substance:
Zinc nitrate to nitrogen dioxide
Write the equation for the process of formation of rust.
Write a note on the following:
Fermentation
Assertion (A): Cutting paper into very small pieces is an irreversible change.
Reason (R): Physical changes are always reversible.
______ is the chemical name of slaked lime.
