Example of Typical Reaction Stoichiometry Problem

In this video, we'll demonstrate how to solve a typical stoichiometry problem using three different methods. Our goal in this problem is to find the amount of water (H2O) formed when starting with 3.2 grams of oxygen (O2). First we'll balance the chemical equation and use the coefficients from the balanced equation as our mole ratios.

The first method involves visually inspecting the mole ratio, where for every one mole of O2, there are two moles of H2O. By doubling the moles of O2 given (0.1 moles), we quickly calculate that 0.2 moles of H2O will be formed. Converting this to grams gives us 3.6 grams of H2O as the final answer.

In the second method, we will employ algebra, using the mole ratio as a simple equation (1 mole O2 = 2 moles H2O). By setting up a proportion and cross-multiplying, we obtain the same result of 0.2 moles of H2O, which we then convert to 3.6 grams.

Lastly, in the third method, we will use the mole ratio, by presenting two valid ratios based on the balanced equation (1 mole O2 = 2 moles H2O and 2 moles H2O = 1 mole O2). We will choose the second ratio to set up a multiplication, and the moles will cancel out to yield 0.2 moles of H2O, which we'll then convert to 3.6 grams.

Stoichiometry problems usually follow a similar pattern, and by converting the given substance to moles, using the mole ratio to determine the moles of the desired substance, and finally converting back to the desired unit (in this case, grams of H2O), we can solve these problems efficiently and accurately.

For more help with mole conversions and more:

[jasonlove]

Thanks Dr.B🎉. Great to see three ways to get to the same answer. I have made so many silly arithmetic errors on exams that i have to do the calc the dimensional analysis way to double check my work. I would also get tripped up on thinking i needed to multiply by 2 for diatomic elements. Thanks for your guidance here👍🏻👍🏻👍🏻

[Felix_-yq]

Thankyou for the video it helped me to do sums regarding stoichiometry
Btw im in class 10 🙂

[henryelicker]

Dr. B is that kinda guy you can just fish and have a beer with while discussing MO theory

[mujassim]

Please make video on solubility of chemical in water

Like alkyl benzene or ether

How they made what is the process

[BarrySRNA]

How did you convert 3.2 G o2 to 0.1 moles?

[MrDino-mfvb]

Can you help in making molecular orbital diagram trick and tutorials