You have two beakers. one contains a solution of hcl at ph = 1.0. the other contains a solution of naoh at ph = 13. into a third beaker, you slowly and cautiously pour 20 ml of the hcl and 20 ml of the naoh. after complete stirring, the ph of the mixture will be
a) 2.0.
b) 12.0.
c) 7.0.
d) 5.0.
e) 9.0

The final pH will be 7.0 (C)

Explanation:

The pH is a scale to measure the concentration of protons in a solution. The followiing equation shows the mathematical definition of pH:

Another important equation is the one correlating the values of pH and pOH, which regards the concentration of hidroxide ions in solution;

, with pKw = 14

Finally, it is necessary to know that when an acidic and an basic solutions are mixed quantitatively, menaing with no excess of hydrogen or hydroxide ions, a neutralization reaction occurs:

HCl + NaOH → NaCl + H₂O

Now, lets calculate the H⁺ and OH⁻ concentrations in both solutions:

HCl: pH = 1.0, which means pH = -log[H⁺] ∴ [H⁺]  = 1 x  10⁻¹ mol/L

NaOH: pH = 13.0, which means pOH = 1.0  pOH = -log[OH⁻] ∴ [OH⁻]  = 1 x  10⁻¹ mol/L

Since the concentrations of H⁺ and OH⁻ are the same and equal volumes of each solutions were used, a neutralization reaction will happen and the final pH will be equal to the pH of water (pKw) which is 7.0.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

it would be d. henry moseley

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