Table of Contents
- 1 Why pure zinc is not used in preparation of hydrogen gas?
- 2 Why metals other than zinc are not used for the laboratory preparation of hydrogen gas?
- 3 Why only granulated zinc is used to prepare hydrogen?
- 4 Why is zinc granules used?
- 5 Which metal is not used to prepare hydrogen?
- 6 Why use zinc granules instead of zinc dust?
Why pure zinc is not used in preparation of hydrogen gas?
(i) Completely pure zinc metal is not used for the preparation of hydrogen because it is slowly attacked by the acid. The presence of impurities increases the rate of the reaction by forming electrochemical couples.
Why zinc granules are preferred over pure zinc during the formation of hydrogen gas?
Granulated zinc is ideal for the preparation of hydrogen gas in chemical laboratories because it usually contains a small amount of copper, which has the ability to act as a catalyst to the associated chemical reaction and, therefore, increase the rate of the chemical reaction without actually participating in it.
Why metals other than zinc are not used for the laboratory preparation of hydrogen gas?
Metals such as Cu, Hg, Ag etc. are less electropositive than hydrogen, as they lie below hydrogen in the reactivity series. Hence, they cannot liberate hydrogen gas from acids.
Why don’t we use concentrated sulphuric acid in the laboratory preparation of hydrogen using zinc granules?
Conc. sulphuric acid is not used because zinc reacts with concentrated acid to form sulphur dioxide gas instead of dihydrogen.
Why only granulated zinc is used to prepare hydrogen?
Now, coming back to our question granulated zinc is preferred to metallic zinc in the preparation of hydrogen because granulated zinc has more surface area exposed to the acid, so the reaction can occur more rapidly.
Why granulated zinc is more reactive than pure zinc?
Granulated zinc gives more surface area for the acid to act, so hydrogen is formed faster. Also, granulated zinc has copper as an impurity, which catalyses the reaction.
Why is zinc granules used?
Why is zinc preferred?
Which metal is not used to prepare hydrogen?
….Since copper is less reactive than hydrogen, it is not able to displace hydrogen from dilute acids.
Is h2so4 an Efflorescent?
– Efflorescent compound is the compound which has water associated with its molecules and it loses the water molecules when exposed to air. Concentrated sulphuric acid actually accepts water molecules from air. So, we can say that sulphuric acid is not an efflorescent compound.
Why use zinc granules instead of zinc dust?
Answer: (a) When zinc dust is taken instead of zinc granules to react with sulphuric acid, the hydrogen gas is formed. But the rate of reaction increases in the case of zinc dust compared to the zinc granules, because of increase in surface area as increase in surface are increases the rate of reaction.