Question

1. The pH of rainwater collected in a certain part of a highly industrialized area on a particular day was 4.82. What is the H+ ion concentration of the rainwater?

2. The OH- ion concentration of a blood sample is 2.5 x 10-7 M. What is the pH of the blood?


Please help me solve this problems :(

Answer 1

Answer on Question #40589 - Chemistry - Other

Question

1. The pH of rainwater collected in a certain part of a highly industrialized area on a particular day was 4.82. What is the H+ ion concentration of the rainwater?

2. The OH- ion concentration of a blood sample is $2.5 \times 10^{-7} \mathrm{M}$. What is the pH of the blood?

Answer:

1. pH equals:

$$\mathrm{pH} = -\lg [\mathrm{H}^{+}]$$

Therefore H+ ion concentration equals:

$$[\mathrm{H}^{+}] = 10^{-\mathrm{pH}}$$ $$[\mathrm{H}^{+}] = 10^{-4.82} = 1.51 \cdot 10^{-5} \mathrm{M}$$

2. pOH equals:

$$\mathrm{pOH} = -\lg [\mathrm{OH}^{-}]$$ $$\mathrm{pOH} = -\lg (2.5 \times 10^{-7}) = 6.6$$

We know that:

$$\mathrm{pH} + \mathrm{pOH} = 14$$

Therefore pH equals:

$$\mathrm{pH} = 14 - \mathrm{pOH} = 14 - 6.6 = 7.4$$

Answer:

1. H+ ion concentration of the rainwater is $1.51 \cdot 10^{-5} \mathrm{M}$

2. pH of the blood is 7.4