Which solution has the greatest number of hydrogen ions?
A. blood, [tex]pH =7.2[/tex]
B. lemon juice, [tex]pH =2[/tex]
C. soda, [tex]pH =3.5[/tex]
D. bleach, [tex]pH =13.5[/tex]
Answer (1)
pH is inversely related to hydrogen ion concentration: lower pH means higher [ H + ] .
Calculate [ H + ] for each solution using [ H + ] = 1 0 − p H .
Compare the calculated [ H + ] values.
Lemon juice has the highest hydrogen ion concentration: l e m o n j u i ce
Explanation
Understanding pH and Hydrogen Ion Concentration We are given the pH values of four different solutions: blood ( p H = 7.2 ), lemon juice ( p H = 2 ), soda ( p H = 3.5 ), and bleach ( p H = 13.5 ). We need to determine which solution has the greatest number of hydrogen ions. Recall that pH is a measure of the hydrogen ion concentration, [ H + ] , and is defined as p H = − l o g 10 [ H + ] . Therefore, the hydrogen ion concentration can be calculated as [ H + ] = 1 0 − p H .
Calculating Hydrogen Ion Concentrations Now, let's calculate the hydrogen ion concentration for each solution:
Blood: [ H + ] = 1 0 − 7.2 ∗ L e m o nj u i ce : [H^+] = 10^{-2} = 0.01 ∗ S o d a : [H^+] = 10^{-3.5}
Bleach: [ H + ] = 1 0 − 13.5
Hydrogen Ion Concentration Values Calculating the values:
Blood: [ H + ] = 1 0 − 7.2 ∗ L e m o nj u i ce : [H^+] = 10^{-2} = 0.01 ∗ S o d a : [H^+] = 10^{-3.5}
Bleach: [ H + ] = 1 0 − 13.5
Comparing Concentrations The hydrogen ion concentrations are:
Blood: [ H + ] = 6.30957344480193 e − 08
Lemon juice: [ H + ] = 0.01
Soda: [ H + ] = 0.00031622776601683794
Bleach: [ H + ] = 3.1622776601683796 e − 14
Comparing these values, we can see that lemon juice has the highest hydrogen ion concentration.
Conclusion Therefore, lemon juice has the greatest number of hydrogen ions.
Examples
Understanding pH levels is crucial in many real-world applications. For example, in agriculture, knowing the pH of the soil helps farmers determine the best crops to grow and the necessary soil amendments. In medicine, maintaining the correct blood pH is vital for proper bodily function. In environmental science, monitoring the pH of water sources helps assess pollution levels and protect aquatic life. The relationship between pH and hydrogen ion concentration is a fundamental concept in chemistry and biology.
