Answer:
a. 2,9x10⁻⁴ M HCl
Explanation:
A solution is considered acidic when its concentration of H⁺ is higher than 1x10⁻⁷. The higher concentration of H⁺ will be the most acidic solution.
a. 2,9x10⁻⁴ M HCl. In water, this solution dissolves as H⁺ and Cl⁻. That means concentration of H⁺ is 2,9x10⁻⁴ M.
b. 4,5x10⁻⁵M HNO₃. In the same way, concentration of H⁺ is 4,5x10⁻⁵M.
c. 1,0x10⁻⁷M NaCl. As this solution doesn't produce H⁺, the solution is not acidic
d. 1,5x10⁻²M KOH. This solution produce OH⁻. That means the solution is basic nor acidic.
Thus, the solution considered the most acidic is a. 2,9x10⁻⁴ M HCl, because has the higher concentration of H⁺.
I hope it helps!
<u>Answer:</u> The mass of water that should be added in 203.07 grams
<u>Explanation:</u>
To calculate the molality of solution, we use the equation:

Where,
m = molality of barium iodide solution = 0.175 m
= Given mass of solute (barium iodide) = 13.9 g
= Molar mass of solute (barium iodide) = 391.14 g/mol
= Mass of solvent (water) = ? g
Putting values in above equation, we get:

Hence, the mass of water that should be added in 203.07 grams