How to Balance Chemical Equations? Practice Problems

Introduction to Balancing Chemical Equations00:00:00

The video introduces a simple trick to balance chemical equations, explaining that balancing is necessary to adhere to the law of conservation of mass, which states that matter cannot be created or destroyed.

Problem 1: Hydrogen and Oxygen to Water00:00:23

The first problem involves balancing the reaction of hydrogen with oxygen to form water. The process begins by counting atoms on both sides and then adjusting coefficients (big numbers) to balance the oxygen and then hydrogen atoms.

Problem 2: Nitrogen and Hydrogen to Ammonia00:02:14

The second problem demonstrates balancing nitrogen reacting with hydrogen to form ammonia. The steps involve counting N and H atoms, then balancing nitrogen by placing a coefficient in front of ammonia, and finally balancing hydrogen by adjusting the coefficient of H2.

Problem 3: Methane and Oxygen to Carbon Dioxide and Water00:03:14

The third problem tackles a slightly more complex reaction: methane reacting with oxygen to form carbon dioxide and water. The video explains counting C, H, and O atoms and then systematically balancing hydrogen first, followed by oxygen, ensuring carbon remains balanced.

Problem 4: Balancing with Polyatomic Ions00:04:27

This section introduces a new type of problem involving polyatomic ions, using calcium sulfate plus sodium nitrate. The key insight is to treat polyatomic ions (like SO4 and NO3) as single units, simplifying the balancing process.

Problem 5: A More Difficult Balancing Problem00:05:58

The final problem is a more challenging one: carbon plus sulfur dioxide yielding carbon disulfide and carbon monoxide. The video walks through counting atoms, prioritizing sulfur, then oxygen, and finally carbon, emphasizing that only coefficients can be changed, not subscripts.