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The words valence and valency have two related meanings in chemistry. Valence describes how easily an atom or radical can combine with other chemical species. This is determined based on the number of electrons that would be added, lost, or shared if it reacts with other atoms.
You may assume the valences of the chemical elements—the number of electrons with which an atom will bond or form—are those that can be derived by looking at the groups (columns) of the periodic table. While these are the most common valences, the real behavior of electrons is less simple.
- What Do Ph and Pka Measurements Tell Us?
- Relating Ph and Pka with The Henderson-Hasselbalch Equation
- Assumptions For The Henderson-Hasselbalch Equation
- Example Pka and Ph Problem
Once you have pH or pKavalues, you know certain things about a solution and how it compares with other solutions: 1. The lower the pH, the higher the concentration of hydrogen ions [H+]. 2. The lower the pKa, the stronger the acid and the greater its ability to donate protons. The pH depends on the concentration of the solution. This is important b...
If you know either pH or pKa, you can solve for the other value using an approximation called the Henderson-Hasselbalch equation: pH = pKa + log ([conjugate base]/[weak acid]) pH = pka+log ([A-]/[HA]) pH is the sum of the pKa value and the log of the concentration of the conjugate base divided by the concentration of the weak acid. At half the equi...
The reason the Henderson-Hasselbalch equation is an approximation is because it takes water chemistry out of the equation. This works when water is the solvent and is present in a very large proportion to the [H+] and acid-conjugate base. You shouldn't try to apply the approximation for concentrated solutions. Use the approximation only when the fo...
Find [H+] for a solution of 0.225 M NaNO2 and 1.0 M HNO2. The Ka value (from a table) of HNO2 is 5.6 x 10-4. pKa = −log Ka = −log(7.4×10−4) = 3.14 pH = pka + log ([A-]/[HA]) pH = pKa + log([NO2-]/[HNO2]) pH = 3.14 + log(1/0.225) pH = 3.14 + 0.648 = 3.788 [H+] = 10−pH = 10−3.788 = 1.6×10−4
2024年5月25日 · An element family is a set of elements sharing common properties. Knowing how to identify families, the elements in each, and their properties can help predict the behavior of unknown elements and their chemical reactions.
2019年10月28日 · There are two ways to say "two" in Mandarin Chinese : 二 (èr) or 兩 (traditional form) / 两 (simplified form) (liǎng). These characters cannot be used interchangeably so it's important to know when it is appropriate to use which form. Here is a guide to understanding which scenario calls for what kind of "two."
2020年1月13日 · A half-cell is half of an electrolytic or voltaic cell, where either oxidation or reduction occurs. The half-cell reaction at the anode is oxidation, while the half-cell reaction at the cathode is reduction . Half-Cell Example. The electrochemical reaction of a Daniell cell may be written as two half-cells. The original equation is: Read More.
2018年10月9日 · This list of the longest words in the English language could score you major points on your next game — if you can remember how to spell them . Some of the words that qualify for the title take hours to pronounce, like the 189,819-letter word for the protein Titin.
