How would the pH value of an aqueous solution change, when the hydronium ion concentration is increased by a factor of 10?

Select one:
a. decreases by 10
b. decreases by 1
c. increases by 1
d. increases by 10

Increasing H⁺ by 10x => pH decreases by 1 unit

Explanation:

In general, adding H⁺ ions to any aqueous solution ALWAYS causes pH values to fall ( decrease ). Just as adding OH⁻ ions to an aqueous solution causes pH values to rise ( increase ).

Here's a simple calculation demonstrating this...

Given 0.01M HCl(aq) => 0.01M H⁺(aq) + Cl⁻(aq) => pH = -log(0.01) = 2.00

Increase [H⁺] by 10x => 0.10M H⁺(aq) => pH = -log[H⁺] = -log(0.10) = 1.00

Solution with higher H⁺ concentration shows pH decreasing by 1 unit.

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Just to support the above statement about adding OH⁻ ions showing an increase in pH values, the following is also provided FYI ..

Given 0.01M NaOH(aq) => 0.01M OH⁻(aq) + Na⁺(aq) => pOH = -log(0.01) = 2.00 => pH = 14 - pOH = 14 - 2 = 12

Increase [OH⁻] by 10x => 0.10M OH⁻(aq) => pOH = -log[OH⁻] = -log(0.10) = 1.00 => pH = 14 - pOH = 14 - 1 = 13

Increasing [OH⁻] by 10x => increasing pH by 1 unit.

Solution with higher H⁺ concentration shows pH decreasing by 1 unit.

Remember, for any aqueous solution ...

=> Adding H⁺   => always decreases pH

=> Adding OH⁻ => always increases pH

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.