Khan Academy

Homeroom with Sal and Wendy Kopp - Wednesday, September 15

Our conversation series with the Yidan Prize Foundation Council of Luminaries continues as Wendy Kopp, founder of Teach For All, joins Homeroom...

Second "Ask Sal anything" session focused on life advice

Sal is running these sessions at Schoolhouse. (https://schoolhouse.world/refer#:~:text=https%3A//schoolhouse.world,Copy%20Link ) . Anyone can sign...

National SAT Practice Test Day 2021

Taking a full-length SAT practice test is one of the best ways to prepare for test day. In this “study with me” style video, you’ll learn how to...

Buffer capacity | Acids and bases | AP Chemistry | Khan Academy

The capacity of a buffer to neutralize added acid or base depends on the concentrations of HA and A⁻ in solution. For a given ratio of [HA] to...

Khan Academy Ed Talks with Fenesha Hubbard - Thursday, September 2

What are the practical next steps for teachers and students to get ready for the next school year? How can teachers identify and help students...

Sal answers questions from attendees at his Schoolhouse.world series

Sal answers questions from attendees at his Schoolhouse.world series. Not too late to join the second session at...

Buffer capacity | Acids and bases | AP Chemistry | Khan Academy

The capacity of a buffer to neutralize added acid or base depends on the concentrations of HA and A⁻ in solution. For a given ratio of [HA] to...

Buffer range | Acids and bases | AP Chemistry | Khan Academy

A buffer has an effective pH range of one pH unit on either side of the pKₐ value for the weak acid. If the pH of a buffer goes out of this range,...

Methods for preparing buffers | Acids and bases | AP Chemistry | Khan Academy

In this video, we'll explore two common methods for preparing buffer solutions. In the first approach, a certain amount of a weak acid (or weak...

Henderson–Hasselbalch equation | Acids and bases | AP Chemistry | Khan Academy

One way to determine the pH of a buffer is by using the Henderson–Hasselbalch equation, which is pH = pKₐ + log([A⁻]/[HA]). In this equation, [HA]...

Properties of buffers | Acids and bases | AP Chemistry | Khan Academy

Buffer solutions contain high concentrations of both a weak acid and its conjugate base (or a weak base and its conjugate acid). Because these...