<span>Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that </span>the concentration of hydrogen ions (H⁺) or hydronium ions (H₃O⁺) in solution X is thousand times as great as the concentration of hydrogen ions or hydronium ions in solution Y.
Solution X: c(H⁺) = 10∧-pH = 10⁻⁴ mol/L = 0,0001 mol/L.
Solution Y: c(H⁺) = 10⁻⁷ mol/L = 0,0000001 mol/L.
0,0001 mol/L / 0,0000001 mol/L = 1000.
Answer:
- <u>Yes, it is 14. g of compound X in 100 ml of solution.</u>
Explanation:
The relevant fact here is:
- the whole amount of solute disolved at 21°C is the same amount of precipitate after washing and drying the remaining liquid solution: the amount of solute before cooling the solution to 21°C is not needed, since it is soluble at 37°C but not soluble at 21°C.
That means that the precipitate that was thrown away, before evaporating the remaining liquid solution under vacuum, does not count; you must only use the amount of solute that was dissolved after cooling the solution to 21°C.
Then, the amount of solute dissolved in the 600 ml solution at 21°C is the weighed precipitate: 0.084 kg = 84 g.
With that, the solubility can be calculated from the followiing proportion:
- 84. g solute / 600 ml solution = y / 100 ml solution
⇒ y = 84. g solute × 100 ml solution / 600 ml solution = 14. g.
The correct number of significant figures is 2, since the mass 0.084 kg contains two significant figures.
<u>The answer is 14. g of solute per 100 ml of solution.</u>
Answer:True
Explanation:
Light year is the unit of distance and not a unit of time.
Light year is used to measure astronomical distances.
It is defined as the distance which light travels in one year.
The distance which light travels in one year is around 9.46 trillion kilometers
Thus 1 light year = 
km.
Thus the given statement that A light-year is the distance that light travels in one year is true.
