https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:basic-concepts-of-chemistry/x426c9d2c554669cb:laws-of-chemical-combination/v/law-of-conservation-of-mass 2023-06-26T12:36:08.867767149Z Law of conservation of mass What happens to mass in a chemical reaction? Does it change or remain the same? Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Law of conservation of mass What happens to mass in a chemical reaction? Does it change or remain the same? Let's find out! https://cdn.kastatic.org/ka-youtube-converted/rnpy_SHsMNg.mp4/rnpy_SHsMNg.mp4 180 Balancing chemical equations https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:basic-concepts-of-chemistry/x426c9d2c554669cb:laws-of-chemical-combination/v/law-of-definite-proportions 2023-06-26T12:36:08.867767149Z Law of definite proportions If we take 10L of water or 10,000L of water, will the ratio of the mass of oxygen to hydrogen in both the samples be same or different? Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Law of definite proportions If we take 10L of water or 10,000L of water, will the ratio of the mass of oxygen to hydrogen in both the samples be same or different? Let's find out! https://cdn.kastatic.org/ka-youtube-converted/IKbOoCrXXIk.mp4/IKbOoCrXXIk.mp4 139 Balancing chemical equations https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:basic-concepts-of-chemistry/x426c9d2c554669cb:laws-of-chemical-combination/e/laws-of-chemical-combination 2026-07-02T04:40:35.242673419Z Laws of chemical combination (basic) Let's solve a few problems to understand the laws of chemical combination. Aanchal Arora exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:balancing-chemical-equations/v/balancing-chemical-equations-introduction 2023-12-18T19:15:22.874322042Z Balancing chemical equations A balanced chemical equation shows the same number of each type of atom on both sides of the arrow. video https://cdn.kastatic.org/googleusercontent/KuGYlI3J-XDdXgteNvXaGiRtfGJ7BYAEIwASrFK3vwIEK0Hg2HRetbOfUB2QH9X_quZiNTrYC8LBuW5oLab5C3E Balancing chemical equations A balanced chemical equation shows the same number of each type of atom on both sides of the arrow. https://cdn.kastatic.org/ka-youtube-converted/TUuABq95BBM.mp4/TUuABq95BBM.mp4 304 Balancing chemical equations https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:types-of-chemical-reactions/x426c9d2c554669cb:different-types-of-chemical-reactions/e/balancing-simple-chemical-equations 2025-03-07T16:50:49.734868403Z Balancing simple chemical equations Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:balancing-chemical-equations/v/balancing-more-complex-chemical-equation 2023-12-18T19:15:22.874322042Z Balancing more complex chemical equations A balanced chemical equation shows the same number of each type of atom on both sides of the arrow. In this example, we balance the combustion reaction of ethylene, C₂H₄, and provide tips on how to balance more complex chemical equations. video https://cdn.kastatic.org/googleusercontent/MpsGPgnDSngc3GCHmDOjYUD16mGSx1mH2zEblVPfeUtyLROPhCn8bk_e2XqbKI4JW4TxPEaJEUBQZoFxycLDQyK3 Balancing more complex chemical equations A balanced chemical equation shows the same number of each type of atom on both sides of the arrow. In this example, we balance the combustion reaction of ethylene, C₂H₄, and provide tips on how to balance more complex chemical equations. https://cdn.kastatic.org/ka-youtube-converted/xqpYeiefZl8.mp4/xqpYeiefZl8.mp4 277 Balancing chemical equations https://www.khanacademy.org/science/bridge-course-class-11th-chemistry/x426c9d2c554669cb:types-of-chemical-reactions/x426c9d2c554669cb:different-types-of-chemical-reactions/e/balanced-chemical-equations 2025-03-07T16:50:49.734868403Z Balancing complex chemical equations Let's solve some questions! vibhor exercise https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/balancing-chemical-equations/v/balancing-chemical-equation-with-substitution 2021-07-14T12:09:10Z Balancing chemical equation with substitution Using the substitution method to balance a reaction where a reactant and product have a polyatomic ion in common.  video https://cdn.kastatic.org/googleusercontent/7UpK3VyO8Dt1XlFyOKOk3PFc0KvWn0Df1DGa10mMiZoqwfIjYHNpGXAMjdQlHgEc2vHxYsUWFnB5gdTrVxtcJFH8 Balancing chemical equation with substitution Using the substitution method to balance a reaction where a reactant and product have a polyatomic ion in common.  https://cdn.kastatic.org/ka-youtube-converted/8KXWJCmshEE.mp4/8KXWJCmshEE.mp4 252 Balancing chemical equations https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:balancing-chemical-equations/v/visually-understanding-balancing-chemical-equations 2023-12-18T19:15:22.874322042Z Visually understanding balancing chemical equations A balanced chemical equation shows the same number of each type of atom on both sides of the arrow. We can relate a balanced chemical equation to the structural formulas of its reactants and products. video https://cdn.kastatic.org/googleusercontent/0w38eUUC_h0aouhDV-TvRWuC445_bCbCllnwINyYdu98DnrJebRCx0Ru4whGW3CYPChV05pF2so1_AsX7M925HjL Visually understanding balancing chemical equations A balanced chemical equation shows the same number of each type of atom on both sides of the arrow. We can relate a balanced chemical equation to the structural formulas of its reactants and products. https://cdn.kastatic.org/ka-youtube-converted/HbIdp5DURJA.mp4/HbIdp5DURJA.mp4 277 Balancing chemical equations https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:balancing-chemical-equations/e/apply-balancing-equations 2026-04-29T07:20:45.495372596Z Apply: Balancing equations Apply your understanding of the conservation of matter in chemical equations in this set of free practice questions. Fig exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:activity-how-can-a-big-log-turn-into-a-tiny-pile-of-ash-when-it-burns/a/activity-how-can-a-big-log-turn-into-a-tiny-pile-of-ash-when-it-burns 2026-01-14T23:20:41.344464701Z Activity: How can a big log turn into a tiny pile of ash when it burns? Make science come alive in your classroom with this free hands-on activity aligned to high school standards. article