pH scale for acidity is defined by pH

Question

The pHpH scale for acidity is defined by pH=−log10[H+]pH=-log10[H+] where [H+][H+] is the concentration of hydrogen ions measured in moles per liter (M).

(A) The pHpH of Milk of Magnesia is 10.5. Calculate the concentration of hydrogen ions in moles per liter (M).

[H+]=[H+]=  M  

(B) The pHpH of lemon juice is 2.0. Calculate the concentration of hydrogen ions in moles per liter (M).

[H+]=[H+]=  M  

Answer 1

Hi Latasha,

The pH scale for acidity is defined by pH=−log10[H+] where [H+] is the concentration of hydrogen ions measured in moles per liter (M).

(A) The pHpH of Milk of Magnesia is 10.5. Calculate the concentration of hydrogen ions in moles per liter (M).[H+]= M

(B) The pHpH of lemon juice is 2.0. Calculate the concentration of hydrogen ions in moles per liter (M).

[H+]= M

Given: Formula for pH=−log10[H+]

Find: [H+]

a) pH = 10.5

pH=−log₁₀[H+]

10.5 = - log₁₀[H+]

-10.5 = log₁₀[H+] // log property to change from log to exponent x=log_ab --> a^x= b

10^(-10.5)= [H+}

[H+] = 3.1622 x 10^-11

Do the same for part b

Hope this helps!