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

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

Determining Precipitate Yield (g) in Aqueous Solution

Given Question: Given the reaction: K3(PO4)+ Ni(SO4)→ K3(SO4)(aq)+Ni(PO4)(s), with 100.0 ml of K3PO4 and 200.0 ml of NiSO4 under standard conditions, how many grams of precipitate form?  Step 1: Determine the limiting reactant and the precipitate.  In order to determine the limiting reactant, one must convert all reactants to moles (mol). In this case, we can … Continue reading Determining Precipitate Yield (g) in Aqueous Solution

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

Balancing Equations (Chem.libretext example)

The point of this exercise is to practice balancing reactions. Many students get overwhelmed when they face having to balance equation usually because it's hard to determine where to start. Given Problem: Lead (IV) Hydroxide and sulfuric acid react as: Pb(OH)4+H2SO4→ Pb(SO4)2+H2O Balance the equation: 1. The first step to balancing a chemical reaction is to identify … Continue reading Balancing Equations (Chem.libretext example)

Determining the Density of a Face-Centered Aluminum Cell

Crystals come in unique shapes, but all usually have an organized, repeating structure known as a lattice. For more information about metal lattices check out: https://www.seas.upenn.edu/~chem101/sschem/metallicsolids.html  Given Problem: An aluminum crystal has a face-centered unit cell. An aluminum atom has a radius of 143 picometers. What is the density of the solid crystal aluminum in g/cm³?  … Continue reading Determining the Density of a Face-Centered Aluminum Cell

Gas Volume Stoichiometry Problem

Given Problem: Methanol (CH3OH) can be synthesized as: CO+2H2→CH3OH. What volume in liters of H2(g) is needed to make 35.7 grams of CH3OH?  1. We are given the temperature at 355 K and the pressure is 738 mmHg. 2.  First, you must convert the target mass of CH3OH to moles. To do this, you use the molar mass … Continue reading Gas Volume Stoichiometry Problem