Answer:
Explanation:
To find the mass percent composition of an element, divide the mass contribution of the element by the total molecular mass. This number must then be multiplied by 100% to be expressed as a percent.
B) Equal to the number of protons
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)
0.16 M is the concentration of a solution prepared by diluting 20.0 ml of 2.00 M NaCl to 250.0 ml.
Explanation:
Data given:
Initial volume of NaCl, V1 = 20 ml
initial molarity of the NaCl solution = 2M
Final volume of the NaCl solution = 250 ml
final molarity of the diluted solution = ?
from the information given, the formula for dilution used is:
Minitial Vinitial = Mfinal Vfinal
putting the values in the rearranged equation:
V final = 
V final = 
Mfinal = 0.16 M
Thus it can be seen that when a 20 ml solution having molarity of 2M is diluted to 250 ml the molarity decreases to 0.16 M.
