Question

the hydrogen ion concentration of a substance is given. calculate the ph of the substance. (round your answers to one decimal place.) (a) milk: h⁺ = 3.2 × 10⁻⁷ m (b) vinegar: h⁺ = 2.0 × 10⁻⁷ m resources read it watch it

Explanation:

Step1: Recall pH formula

The formula for pH is $pH = -\log_{10}[H^{+}]$.

Step2: Calculate pH for milk

For milk with $[H^{+}]=3.2\times 10^{-7}\ M$, we substitute into the formula: $pH = -\log_{10}(3.2\times 10^{-7})$. Using the logarithm property $\log(ab)=\log(a)+\log(b)$, we have $pH = -(\log_{10}(3.2)+\log_{10}(10^{-7}))$. Since $\log_{10}(10^{-7})=- 7$ and $\log_{10}(3.2)\approx0.505$, then $pH=- (0.505 - 7)=6.5$ (rounded to one - decimal place).

Step3: Calculate pH for vinegar

For vinegar with $[H^{+}]=2.0\times 10^{-7}\ M$, we substitute into the formula: $pH = -\log_{10}(2.0\times 10^{-7})$. Using the logarithm property $\log(ab)=\log(a)+\log(b)$, we get $pH=-(\log_{10}(2.0)+\log_{10}(10^{-7}))$. Since $\log_{10}(10^{-7})=-7$ and $\log_{10}(2.0)\approx0.301$, then $pH=- (0.301 - 7)=6.7$ (rounded to one - decimal place).

Answer:

(a) 6.5
(b) 6.7