Chemical equations must be balanced to equate the number of atoms of reactants and products. As the law of conservation of mass states, “Mass can neither be created nor be destroyed but can be changed from one form to another.” Hence, the total mass of the reactant must be equal to the total mass of the products. For example, Na + H2O → NaOH + H2 ( Unbalanced equation ) The total mass of the reactants is 23+18= 41grams whereas the total mass of the products is 40+2=42 grams. This means that this equation needs to be balanced. 2Na + 2H2O → 2NaOH + H2 ( Balanced equation ) Now, the reactants have a total mass of 82grams {(23×2=46) + (18 x 2=36)} and the products formed must have 82grams {(40×2=80) + (2 x 1=2)}. Rules for Balancing Chemical Equations
Additional links:
Moderators: Chem_Mod, Chem_Admin
Madelyn Cearlock Posts: 72 Joined: Fri Sep 28, 2018 12:19 am
For the question that asks why do we balance chemical equations, what was the exact answer that was desired? Thank you!
Christopher Tran 1J Posts: 77 Joined: Fri Sep 28, 2018 12:15 am
Balancing chemical equations makes sure that the number of moles of reactants and products are the same, and therefore agree with the law of conservation of mass.
Marwan Masri 3B Posts: 31 Joined: Fri Sep 28, 2018 12:23 am
if the number of atoms of each element is not the same on both the reactants and the products side, the law of conservation of mass would be violated.
Kobe_Wright Posts: 83 Joined: Fri Sep 28, 2018 12:16 am
I put to conserve the law of conservation of mass and I got it right.
Karishma_1G Posts: 67 Joined: Fri Sep 28, 2018 12:18 am
I said that we balance them because of the law of conservation of mass which states that matter cannot be created nor destroyed.
Xinyi Zeng 4C Posts: 63 Joined: Fri Sep 28, 2018 12:18 am
I wrote "to make sure the law of conservation of mass is obeyed as there should be equal number of atoms of the same element on both sides of the reaction equation", and I got full credit for it. I think the most essential part of the answer is "the law of conservation of mass".
Nathan Mariano 2G Posts: 68 Joined: Fri Sep 28, 2018 12:29 am
We balance chemical equations due to the law of conservation of mass, which states that mass can neither be created or destroyed. Therefore, in a chemical reaction, the total mass of the reactants must be equal to the total mass of the products. Balancing equations accounts for the total mass of the reactants and the total mass of the products.
Jack Hewitt 2H Posts: 67 Joined: Fri Sep 28, 2018 12:27 am
Because of the law of conservation of mass.
duenezjuleny1D Posts: 48 Joined: Fri Sep 28, 2018 12:24 am
We want to make sure not break the law of conservation of mass. It is important to balance on each side, the products and the reactants.
Brian Kwak 1D Posts: 88 Joined: Fri Sep 28, 2018 12:17 am
It is because of the concept of conservation of mass which states that in an isolated system mass can not be created nor destroyed by chemical reactions or physical transformations. Since the chemical reaction can not destroy or create mass the number of elements from the reactants must equal the number of elements that are produced.
Yasmin Olvera 1D Posts: 29 Joined: Thu Feb 14, 2019 12:15 am
To show the conservation of mass. Also my TA said not to assume every chemical equation we get on the exam will be balanced. He said to verify everytime we are presented with an equation to check ourselves that it is balanced.
Karolina herrera1F Posts: 33 Joined: Sat Feb 02, 2019 12:15 am
This would be to show the conservation of mass a chemical equation must have an equal number of each type of atoms on both sides of the reaction arrow.
Joanne Lee 1J Posts: 100 Joined: Thu Jul 25, 2019 12:15 am
According to the law of conservation of mass, during a chemical reaction, mass is neither created or destroyed so the equation must be balanced in order to follow this law. Return to “Balancing Chemical Reactions”
Users browsing this forum: No registered users and 1 guest |