Question
Define adsorption. Why students can read blackboard written by chalks?

Answer

  • Adsorption is the phenomenon of accumulation of higher concentration of ‘one substance on the surface of another (in bulk) due to unbalanced/unsatisfied attractive forces on the surface.
  • When we write on blackboard using chalk, the chalk particles get adsorbed on the surface of the blackboard.

Hence, students can read blackboard written by chalks.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Mention features of Mendeleev’s periodic table.
Chalcopyrite $(CuFeS_2)$ is a common ore of copper. Since it has low concentration of copper, the ore is first concentrated through froth floatation process. The concentrated ore is then heated strongly with silicon dioxide $($silica$)$ and oxygen in a furnace. The product obtained, copper$(I)$ sulphide, is further converted to copper $(99.5\%$ pure$)$ with a final blast of air $(O_2)$ during which sulphur dioxide is released as a by$-$product.
$i.$ Write a balanced reaction for the extraction of copper from copper$(I)$ sulphide.
$ii.$ Which species undergoes an increase in the oxidation state?
$iii.$ Which species accepts electrons?
Write down structural formulae of $(i)$ the third higher and $(ii)$ the second lower homologue of $CH_3CH_2COOH.$
$65 \%$ of ${ }^{111}$ In sample decays in $4.2 d$. What is its half life?
Answer:
Given: $N _0=100$,
$
N=100-65=35 \text {, }
$
$
t=4.2 d
$
To find: $t_{1 / 2}$
In an experiment conducted to study the diffusion of gases using same experimental conditions, following data were recorded.
Gas $A: 50 \ cm^3$ of gas $A$ takes $7$ minutes to diffuse from one container to the adjacent container.
Gas $B: 50 \ cm^3 $of gas $B$ takes $10$ minutes to diffuse from one container to the adjacent container.
$i.$ What is the rate of diffusion of gas $A$?
$ii.$ What is the rate of diffusion of gas $B$?
$iii.$ Which gas has higher molecular mass?
Write a short note on continuous extraction method.
Write a note on occurrence of group 1 and group 2 elements:
What is the adsorption Isotherm?
Explain (n + l) rule with respect to energies of orbitals.

Complete The Chart :
Image