16.2 Hydrogen Ions and pH Assignment: Ion product of Water

What occurs during the self-ionization of water?

• the pH of the solutions increases, and the pOH decreases

• a hydroxide is transferred from one water to another forming an acid and a base

• a neutralization reaction occurs forming a salt and water

• a proton is transferred from one water to another forming a hydronium ion and a hydroxide ion

What is the concentration of OH^– in pure water?

• 10^–7 M

• 0.7 M

• 55.4 M

• 10⁷ M

What is the product of H₃O⁺ and OH^– concentrations in water?

• 10^–28

• 10^–7

• 55.4

• 10^–14

The Kw at room temperature (25 degrees C) is equal to 1.0 x 10-14.  It can also be defined as:

• the pH and pOH of a solution

• the product of the hydronium ion and the hydroxide ion concentrations

• -log [hydronium ion]

• antilog -pH

If the hydronium ion H₃O⁺ concentration is equal to the hydroxide ion OH^- concentration, the solution is a(n)

• acid

• base

• salt

• neutral solution

A solution of Ca(OH)₂ is 1.0 x 10^-5 M. What is the hydronium ion concentration?

• 1.0 x 10^-5 M

• 1.0 x 10^-9 M

• 5.0 x 10^-10 M

• 2.0 x 10^-5 M

Tags

NGSS.HS-PS1-7

What is the OH^- concentration for a 1.0 E-2 M solution of NaOH?

• 1.0 E-12 M OH^-

• This cannot be determined from the information given.

• 2

• 1.0 E-2 M OH^-

Tags

NGSS.HS-PS1-7

What is the concentration of hydroxide ions in a 2.0 M HCl solution?

• 5.0 E-15 M OH^-

• 2.0 M OH^-

• 2.0/1.0 E-14 M OH^-

• antilog (-2.0)

A solution with a [H+] of 9.4 x 10^-5 mol/L is said to be

• Acidic
• Basic
• Neutral
• negative number, no solution.

Hydrochloric acid (HCl) is a strong acid, meaning that it is essentially 100% ionized in solution. What are the values of [H+] and [OH−] in a 2.0 × 10⁻³ M solution of HCl?

*use K_w = 1.0 × 10⁻¹⁴ *

• [H+]= 2.0 × 10⁻³ M; [OH−]=5.0 × 10⁻¹² M

• [H+]= 2.0 × 10³ M; [OH−]=5.0 × 10⁻¹² M

• [H+]= 2.0 × 10^-3 M; [OH−]=5.0 × 10¹² M

• [H+]=5.0 × 10⁻¹² M ; [OH−]= 2.0 × 10⁻³ M