Practice Problem: Gibbs Free Energy

Given Question: The reaction given above is accompanied by the Enthalpy of the reaction (H) and the entropy (S). Determine the change in Gibbs Free energy (G) and if the reaction is spontaneous or not. If the reaction isn't spontaneous, calculate the temperature in which it will be.  Start off by listing what we know, … Continue reading Practice Problem: Gibbs Free Energy

Episode 5b: Combustion Reactions

Episode 5B: Combustion Reactions   This episode is on FIRE! All about combustion reactions and the information we can gain from them. Misspeak at ~5:57, should be grams hydrogen. Music: Good For You by THBD https://soundcloud.com/thbdsultan Creative Commons — Attribution 3.0 Unported— CC BY 3.0 http://creativecommons.org/licenses/b... Music provided by Audio Library https://youtu.be/-K_YSjqKgvQ Find us at … Continue reading Episode 5b: Combustion Reactions

Lesson 5a: Theoretical, Actual, and Percent Yield.

    In which we explore theoretical and actual yields! And I make a personal record of how many times I can say, "My bad" onscreen. Trouble accessing the video? Check us out on YouTube!  Questions, comments, concerns? Email us at heychemistryblog@gmail.com. Science rules!! x

Work Problem: Calculation of Molar Mass of Unknown Base Using Titration With a Strong Acid

Given Question: A student titrates 2.0135 grams of an unknown monobase weak base to the equivalence point with 67.02 mL of .5003 M HCl(aq). What is the molar mass of the weak base?  Step 1: This is to sort out what we're given in the equation, as well as some previous knowledge. We'll use the first … Continue reading Work Problem: Calculation of Molar Mass of Unknown Base Using Titration With a Strong Acid

Interview with James Nowick- Researcher, Educator, Advocate.

HeychemTutor got a chance to sit down with esteemed professor and advocate Dr. James Nowick, who is currently based out of the University of California-Irvine. We sat down to discuss chemistry, LGBTQIA+ rights, and advocacy. This was a project Heychem set in celebration of June 2017 Pride month. Contact us with questions, concerns, or complications … Continue reading Interview with James Nowick- Researcher, Educator, Advocate.

Determining the Molar Solubility of Iron (II) Hydroxide

Given Question: Calculate the molar solubility of Fe(OH)2 (Ksp=4.87*10^-7).  Tutor's Note: The Ksp radical that's written down comes in later, I got confuzzled by my own notes! Happens to all of us. Sorry students 🙂  Step 1: Write out the reaction equation with all ions. Make sure it's balanced! We'll use this in the next step with … Continue reading Determining the Molar Solubility of Iron (II) Hydroxide

Calculating the pH of a Buffer System

The point of this problem is to correctly calculate the pH of a buffer system using formonitrile, or hydrogen cyanide. Here, we use the dissociation constant and the Henderson-Hasselbach equation. Given Problem: Calculate the pH of a buffer that's .250 M HCN (kª= 4.9*10^-10) and 0.170 M KCN.  2. This is to remind us of the … Continue reading Calculating the pH of a Buffer System

Titration of Strong Acid With Strong Base

The goal of this example is to help students become fluent in calculating pH/pOH of a solution during a titration of a strong acid (HCl) and a strong base (NaOH). This problem includes calculations for titrations of increasing volumes. Given Problem: Calculate the pH of a titration of 25.0 mL of HCl (.100 M) with … Continue reading Titration of Strong Acid With Strong Base

Calculating Acid:Buffer Ratio using H-H Equation

Given Question: Which acid would you combine with its Na (sodium) sat to create a buffer with a pH of 7.35. What ratio of a buffer to acid is needed? There are 3 potential buffers provided to choose from. 1. First, we choose which buffer is the best acid to choose to obtain the desired … Continue reading Calculating Acid:Buffer Ratio using H-H Equation