1.0 mole ---------- 6.02x10²³ molecules
4.5 moles -------- ?
4.5 * 6,02x10²³ / 1.0
= 2.709x10²⁴ molecules units
A saturated solution is one in which no more solute is able to dissolve in a given solvent at a particular temperature. Some amount of the solute is left undissolved in the solution.
Unsaturated solution has solute in lower proportions than required to form a saturated solution.
Supersaturated solution has solute in amounts greater than a saturated solution.
We can take the help of solubility curve in order to find out the amount of a salt required to prepare a saturated solution of that salt at a particular temperature.
The solubility of KI at 10
is 136 g/ 100 mL water
The solubility of 
at 
is 21 g/100 mL water.
The solubility of 
at is 80 g/100 mL water.
The solubility of NaCl at is 38 g/ 100 mL water.
So the correct answer will be KI, as it would need 136 g KI / 100 mL water to form a saturated solution at .So, if we have 80g KI/ 100mL water it would be an unsaturated solution.
Explanation:
A mixture in which there is uniform distribution of solute particles into the solvent is known as a homogeneous mixture.
For example, sugar dissolved in water is a homogeneous mixture.
On the other hand, a mixture in which there is uneven distribution of solute particles into the solvent is known as a heterogeneous mixture.
For example, sand present in water is a heterogeneous mixture.
Comment on given situations will be as follows.
(a) Air in a closed bottle - It is a homogeneous mixture because there will be even distribution of other gases that are present in air.
(b) Air over New York City - It is a heterogeneous mixture because there will be presence of some dust particles, fog or smoke into the air. Distribution of all these particles will be uneven. This will make air over New York City heterogeneous in nature.
Answer:
1.8 × 10² cal
Explanation:
When 0.32 g of a walnut is burned, the heat released is absorbed by water and used to raise its temperature. We can calculate this heat (Q) using the following expression.
Q = c × m × ΔT
where,
c: specific heat capacity of water
m: mass of water
ΔT: change in the temperature
Considering the density of water is 1 g/mL, 58.1 mL = 58.1 g.
Q = c × m × ΔT
Q = (1 cal/g.°C) × 58.1 g × 3.1°C
Q = 1.8 × 10² cal
