Given Questions: 155.8 Kg of SiO2 reacts with 78.3 Kg of Carbon to produce 66.1 Kg of silicon. What is the percent yield of the reaction? 1. The first step is to convert your given masses into moles. This way, you can see which reactant is in excess and which one is limiting. A good … Continue reading Calculating Percent Yield

# Month: November 2016

# Calculating Final Temperature of Heated Al in H2O (Example)

Given Problem: A block of Aluminum has a mass of 32.5 grams and is at 45.8° C. It's placed in 105.3 grams of water at 15.4° C. What's the final temperature for both the aluminum and water? 1. These are the equations we're going to use. Because we have two equations for q, we can substitute … Continue reading Calculating Final Temperature of Heated Al in H2O (Example)

# Calculating Temperature Change Using Q=mCsΔT

This problem is designed to get you comfortable working with the equation given, and is good because it gets you to think of Q in terms of joules. Given Problem: 25 grams of gold (Au) is initially at 27°C. It absorbs 2.35 kJ of heat. What is the final temperature of the gold? The specific heat … Continue reading Calculating Temperature Change Using Q=mCsΔT

# 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)

# Determining Empirical Formula (Example)

The outcome of this problem is to understand how to find the empirical formula of the unknown reactant in this combustion reaction. Given Problem: The combustion reaction X+O2→ CO2 + H2O contains 1.29 grams of X reactant, where X is an unknown compound containing C,H, & O. The reaction yields 1.13 grams of H2O and 2.086 … Continue reading Determining Empirical Formula (Example)

# Episode 3: Compounds

Corrections below! Episode 3: Compounds Content: -Introduction -Formulas for Compounds -Diatomic/Polyatomic molecules -Naming Ionic, Covalent, and Transition metal compounds -Example problems Corrections!: -The empirical formula for C6H12O6 is CH2O, not C3H4O3 - The carbonate ion (CO3) has a 2- charge, not a 1-. Video troubles? Check out our YouTube channel! Questions? Comments? Feedback? Leave us … Continue reading Episode 3: Compounds

# 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

# Episode 2: Atoms and Elements

Video Content: -Atomic Theory -Atomic Structure -Ions vs. Isotopes -Example Problem Published November 13th, 2016 Thank you for using Heychemistry.com! Have any feedback? Reach us via our contact page! Video troubles? Try the YouTube link.

# Episode 1: Introduction to Chemistry

Video play troubles? Here's the YouTube link. Content: Introduction, unit conversions, significant figures, scientific notation & example problems. Corrections: Miles to Km Conversion problem: 542 miles * (109/68)= ~867 km, not 917. Sorry guys! My bad. Video created: November 12th, 2o16.