Advertisements
Advertisements
प्रश्न
What do you observe when a piece of sodium is dropped into cold water?
Advertisements
उत्तर
When a piece of sodium metal dropped in cold water we observe: Sodium floats on water surface melts forming a silvery globule which darts about the surface of water catches fire and burns with golden yellow flame.
Bubbles of hydrogen evolve and solution is soapy, slightly warm (alkaline) hence turns red litmus blue.
APPEARS IN
संबंधित प्रश्न
Indicate which of the following statement is true and which is false:
The hydrogen molecule is monovalent.
Hydrogen is combustible as well as a supporter of combustion.
Hydrogen is a good reducing agent: What do you understand by the above statement? Explain with the help of copper oxide as an example.
MULTIPLE CHOICE QUESTIONS
Which is the lightest of all elements?
- hydrogen
- helium
- lithium
- none of these
FILL IN THE BLANK
The compounds of carbon and hydrogen are called .................
FILL IN THE BLANK
Ammonia is used to make ................
Write the balanced equation and give your observation when the following metal reacts:
Sodium with cold water
Give equations for the reactions.
With reference to the equation : Cl2 + H2S → 2HCl + S pertaining to a redox reaction – select the correct answer.
Chlorine acts as an ______ agent.
Give balanced equation for the following conversion:
Iron [III] oxide to iron – using hydrogen.
Give reason for the following:
The reaction of chlorine with hydrogen sulphide is deemed a redox reaction.
When steam is passed over red-hot iron, magnetic oxide of iron and hydrogen are obtained. “The reaction between steam and red-hot iron is a Reversible Reaction.” What is meant by this statement.
How can you obtain hydrogen from sodium hydroxide [not by electrolysis].
Write balanced equation for the following reaction:
magnesium + dil. hydrochloric acid → ___
Name a gas which burns in air or oxygen forming water.
Complete and balance the following equations:
Al + NaOH + ____ → ____ + ____
Describe briefly, with equations, the Bosch Process for the large scale production of hydrogen.
Give balanced equation for obtaining hydrogen from cold water using a divalent active metal.
Give a reason for the following.
A mixture of hydrogen and chlorine can be separated by passage through a porous pot.
