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.
Education
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
Profile: Amadeo Avogadro
Lorenzo Romano Amedeo Carlo Avogadro, conte di Quaregna e Cerreto or as we know him, Amedeo Avogadro, was born on August 9th, 1776 in Turin, Italy. His father, a lawyer turned senator in Italy, Avogadro began his education in the pursuit of law. Avogadro earned his law degree in 1792, but did not start practicing … Continue reading Profile: Amadeo Avogadro
VSEPR Theory Examples (chem.purdue)
Given Problem: Draw the Lewis dot structures, identify the molecular geometry, and give the bond angle for the following compounds: BeF2 BCl3 SI6 1. BeF2: The first step is to draw the Lewis dot structure. This can be done by identifying how many bonding groups are involved. A bonding group, counts as 1 lone electron, an electron pair, … Continue reading VSEPR Theory Examples (chem.purdue)
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
Finding Wavelength of Light (nm) Using Frequency (Hz)
The point of this problem is to be able to use the c=λν to find the wavelength of light. This problem could also be structured to find the frequency of the light using just the wavelength. 1. The equation we're working with has two values already entered in it. The speed of light (3.00*10^8 m/s) … Continue reading Finding Wavelength of Light (nm) Using Frequency (Hz)
Percent Mass Composition Example
The point of these problems is to calculate the mass of a specific element in a given compound. We're given 88.07 grams of C4H8S, and the molar mass of sulfur is 32.07 grams/mol. We know that the % mass composition is found by dividing the molar mass of our target element by the total mass … Continue reading Percent Mass Composition Example
