➢ Q: Why does NaCl conduct electricity in the liquid state, not in the solid state?
A:
When NaCl dissolves in water or fused (melt) its ions can freely move. Due to
the flow of ions salt easily conduct electricity in a liquid state but in a solid
state, ions are tightly packed they are not able to freely move.
➢ Q: Why does salt easily dissolve in
water?
A:
Salt and water both are polar and they are inorganic compounds. Due to this reason, it dissolves in water in ease.
➢ Q: Why petrol does not mix with
water?
A:
It is because that petrol is an organic compound and non-polar substance while
water is an inorganic compound and polar substance, So, therefore, petrol does
not dissolve in water. They both are heterogeneous.
➢ Q: Graphite and diamond both are
forms of carbon but graphite is a good conductor and diamond is bad why?
A:
graphite and diamond both are forms of carbon but despite graphite is a good
conductor and diamond is not because graphite is soft along with that its ions smoothly
move. On the other hand, diamond is hard and their ions are tightly packed, due
to tightly packed, they are not able to move that is why diamond is a bad
conductor.
➢ Q: Graphite is a good conductor but does not
pass the light why?
A:
graphite does not pass the light despite being a good conductor because it is
an opaque colour as darkness does not let light pass.
➢ Q: Diamond is a bad conductor but it
does pass the light why?
A:
It is because diamond is transparent in a colour that is why it easily passes
the light.
➢ Q: Why does petrol rapidly evaporate?
A:
Since petrol is an organic compound its force of attraction is very less due to
which when it reacts with air it instantly evaporates.
➢ Q: Why do solids directly change into
gas in the sublimation process?
A:
During the sublimation process those solids like Naphthalene are chosen that
possess less force of attraction as they can pass directly without going
through the liquid state and due to less force of attraction in their molecules
solids directly change into a gas without passing from the liquid state.
➢ Q: Why water is a universal solvent?
A:
Because water dissolves many things easily. The dissolving capacity in water is
high due to the presence of hydrogen bonding.
➢ Q: What is the salt bridge and why do
we use it?
A:
Salt bridge is a device that is used in the electrochemical cell. We use it
because it prevents the mixing of two solutions (anode and cathode) and
maintains neutrality between two solutions.
➢ Q: Why does sugar easily dissolve in
hot water than cold?
A:
Because by increasing the temperature solubility also increases so this is the reason
sugar easily dissolves in hot water than cold water.
➢ Q: What is the colour of
phenolphthalein in acid and base?
A:
colourless in acidic solution and pink colour in basic medium
➢ Q: What is D2O and what is
the molecular mass of D2O?
A:
D2O is an isotope form of hydrogen called deuterium oxide and is
also known as heavy hydrogen. The molecular mass is 20.
➢ Q: Why water is less heavy than deuterium
oxide?
A:
Because the molecular mass of deuterium oxide is 20 and the molecular mass of
water is 18. This is the reason that water is less heavy than deuterium
➢ Q:
What is a buffer solution?
A:
A solution that resists changing the pH of the solution. It is used when we
have to maintain the pH of a solution. As there are several elements and solutions
which changes the pH in opening air.
➢ Q: Which element has no neutron?
A:
Hydrogen is merely in the periodic element that does not contain any neutron.
➢ Q: Which
metal is in liquid form?
A:
mercury is merely metal in the periodic table that dwells in the liquid form. Therefore,
in measuring temperature it is mostly used, but it is toxic as well, as it instantly
reacts with air and makes it polluted as well as hazardous for inhaling purposes.
