Answer:
a) Unsaturated
b) Supersaturated
c) Unsaturated
Explanation:
A saturated solution contains the <u>maximum amount of a solute that will dissolve in a given solvent at a specific temperature</u>.
An unsaturated solution contains <u>less solute than it has the capacity to dissolve. </u>
A supersaturated solution, <u>contains more solute than is present in a saturated solution</u>. Supersaturated solutions are not very stable. In time, some of the solute will come out of a supersaturated solution as crystals.
According to these definitions and considering that the solubility of KCl in 100 mL of H₂O at <u>20 °C is 34 g</u>, and at <u>50 °C is 43 g</u> we can label the solutions:
a) 30 g in 100 mL of H₂O at 20 °C ⇒ unsaturated
b) 65 g in 100 mL of H₂O at 50 °C ⇒ supersaturated
c) 42 g in 100 mL of H₂O at 50 °C and slowly cooling to 20 °C to give a clear solution <u>with no precipitate</u> ⇒ unsaturated (if it were saturated it would have had precipitate)
The number<span> of protons in the nucleus of an </span>atom is equal to <span>the </span><span>atomic number of an element. You can also find it by subtracting the number of neutrons from the atomic mass. Atomic Number = Atomic Mass - No. of Neutrons.</span>
Answer:
B) K⁺, Sr²⁺ , O²⁻
Explanation:
Potassium is present in group one. It is alkali metal and have one valance electron.Potassium need to lose its one valance electron and form cation to get complete octet.
That's why it shows K⁺.
Sr is alkaline earth metal. It is present in group two. It has two valance electrons. Strontium needed to lose its two valance electrons and get stable electronic configuration.
When it loses its two valance electrons it shows cation with charge of +2.
Sr²⁺
Oxygen is present in group 16. It has sex valance electrons. It needed two more electrons to complete the octet. That's why oxygen gain two electron and form anion with a charge of -2.
O²⁻
The boiling point depends on the strength of the intermolecular forces holding the molecules together. Greater the force, higher is the boiling point.
The intermolecular force increases in the order shown below:
ion-ion > H-bonding > dipole-dipole > London dispersion
CH3CN is a polar molecule with strong dipole-dipole forces
CH3CH2CH3 is non-polar held by london dispersion
Ar exist as a gas. It will have a lowest boiling point
Thus the order of decreasing b.pt is:
CH3CN > CH3CH2CH3 > Ar
