Question 54 of 69beginner🔧 ApplyNumerical2 marks

The pH of milk, black coffee, tomato juice, lemon juice and egg white are 6.8, 5.0, 4.2, 2.2 and 7.8 respectively. Calculate corresponding hydrogen ion concentration in each.

Correct Answer

(Black coffee) 1.0×10−51.0 \times 10^{-5} M

(Egg white) 1.58×10−81.58 \times 10^{-8} M

(Lemon juice) 6.31×10−36.31 \times 10^{-3} M

(Milk) 1.58×10−71.58 \times 10^{-7} M

(Tomato juice) 6.31×10−56.31 \times 10^{-5} M

Exercise: EXERCISES | Q: 6.56 | (Page 46)
For More Understanding

Explanation

The relationship between pH and hydrogen ion concentration is given by the formula pH=−log⁡10[H+]pH = -\log_{10}[H^+]. To find the hydrogen ion concentration, we rearrange the formula to [H+]=10−pH[H^+] = 10^{-pH}. By substituting the given pH values for each substance into this formula, we can calculate their respective hydrogen ion concentrations.

Solution Steps

  1. Formula: The hydrogen ion concentration is calculated using [H+]=10−pH[H^+] = 10^{-pH}.

  2. Milk: Given pH=6.8pH = 6.8. [H+]=10−6.8=1.58×10−7[H^+] = 10^{-6.8} = 1.58 \times 10^{-7} M

  3. Black coffee: Given pH=5.0pH = 5.0. [H+]=10−5.0=1.0×10−5[H^+] = 10^{-5.0} = 1.0 \times 10^{-5} M

  4. Tomato juice: Given pH=4.2pH = 4.2. [H+]=10−4.2=6.31×10−5[H^+] = 10^{-4.2} = 6.31 \times 10^{-5} M

  5. Lemon juice: Given pH=2.2pH = 2.2. [H+]=10−2.2=6.31×10−3[H^+] = 10^{-2.2} = 6.31 \times 10^{-3} M

  6. Egg white: Given pH=7.8pH = 7.8. [H+]=10−7.8=1.58×10−8[H^+] = 10^{-7.8} = 1.58 \times 10^{-8} M

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