how many moles of hydrogen ions are present in a 2L solution with a pH of 2.75​

Question

how many moles of hydrogen ions are present in a 2L solution with a pH of 2.75​

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Thiên Hương 6 months 2021-07-27T16:14:33+00:00 2 Answers 5 views 0

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    0
    2021-07-27T16:16:07+00:00

    Answer:

    3.556x 10^-3mol

    Explanation:

    Using pH =-log [ H+], we can calculate the concentration of the hydrogen Ions.

    pH =-log [ H+], pH = 2.75

    2.75 = -log[H+], taking antilog of both sides

    10^ — 2.75 = [H+]

    [H+] =1. 778 x 10^-3M

    Now that we have the concentration and also knows the volume, we can use the relation

    Moles = concentration X volume

    = 1. 778 x 10^-3M x 2L = 3.56x 10^-3mol

    The moles of the hydrogen Ions is 3.56x 10^-3mol

    0
    2021-07-27T16:16:28+00:00

    We are given:

    Volume = 2 L

    pH = 2.75

    Finding the concentration required:

    we know that pH is just the negative log of the hydrogen ion concentration

    pH = -log[H⁺]

    we are given that the pH is 2.75

    2.75 = -log[H⁺]

    log[H⁺] = -2.75                         [multiplying both sides by -1]

    10^{log[H]} = 10^{-2.75}                      

    [H⁺] = 1.78 * 10⁻³ Molar

    Number of moles of Hydrogen ions:

    [H⁺] = 1.78 * 10⁻³ Molar

    which means that there are 1.78 * 10⁻³ moles of hydrogen ions in 1 liter solution

    1.78 * 10⁻³ moles / L

    multiplying and dividing by 2, we get:

    3.56 * 10⁻³ moles / 2 L

    Hence we need 3.56 * 10⁻³ moles of hydrogen ions  

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )