Which of the following equations are balanced? Balance those that need it.
a. CaC₂ + 2 H₂O → Ca(OH)₂ +C₂H₂
b. C₂H₈N₂ + 2 N₂O₄ → 2 N₂ + 2 CO₂ + 4 H₂O
c. 3 MgO + 2 Fe → Fe₂O₃ + 3 Mg
d. N₂O → N₂ + O₂

Question

Which of the following equations are balanced? Balance those that need it.

a. CaC₂ + 2 H₂O → Ca(OH)₂ +C₂H₂

b. C₂H₈N₂ + 2 N₂O₄ → 2 N₂ + 2 CO₂ + 4 H₂O

c. 3 MgO + 2 Fe → Fe₂O₃ + 3 Mg

d. N₂O → N₂ + O₂

Accepted Answer

Welcome back, everyone. We need to determine which of our given equations is a balanced equation. Beginning with equation A, we want to compare our reactive side to our product side. So we have magnesium where on a reactive side, we have one mole of magnesium, we have carbon, where on our reactant side, we have two moles of carbon, we have hydrogen. Where on our reactant side, we have four moles of hydrogen because we would take the coefficient times the subscript. And then for oxygen, we have one mole of oxygen or sorry, two moles of oxygen since we have that coefficient of two. Now for our product side, for a choice A we have again, one mole of magnesium. On the product side. For oxygen, we have two moles of oxygen. For hydrogen. On the product side, we have four moles of hydrogen. And for carbon on the product side, we have two moles of carbon based on what we've noted down, everything checks out as balanced. Meaning that example, A is definitely a correct answer choice so far because it's a balanced equation. Now let's move on to choice B where we compare again, the reactant side to the product side. So let's split things up. So for choice B, we have, this is a, this is B, we have our Adam calcium on the reactant side where we have three moles of calcium oxygen, where we have three moles of oxygen and iron, where we have two moles of iron. Then compared to our product side, we have one mole of calcium on the product side, two moles of iron on the product side, and three moles of oxygen. On the product side, we can see that our atoms of calcium do not balance out. And so therefore, this is not balanced. So we would rule out choice B as a correct choice. Now, moving on to choice C. So we'll keep the colors consistent for choice C. We have carbon where we have two moles of carbon on the reactant side, oxygen, four moles of oxygen on the reactant side. And then on our product side, we have two moles of carbon on the product side and two moles of oxygen on the product side. So this does not, our oxygen atoms do not match on both sides. And so therefore, this equation is not balanced. So we would rule out choice C and that leaves us with choice D. Next in which on our react inside, we have one mole of carbon, we have four moles of hydrogen and we have two moles of oxygen. And on our product side, we have one mole of carbon, Two moles of oxygen or sorry, three moles of oxygen. And for our hydrogen, we have two moles of hydrogen. So we can see that our hydrogen does not match up nor does our oxygen. And so therefore, this equation is not balanced. So we can rule out choice D as well. That means our only correct answer. Choice to complete this example is choice A which is the only example of a correctly balanced equation. So I hope this made sense and let us know if you have any questions.

Which of the following equations are balanced? Balance those that need it.
a. CaC₂ + 2 H₂O → Ca(OH)₂ +C₂H₂
b. C₂H₈N₂ + 2 N₂O₄ → 2 N₂ + 2 CO₂ + 4 H₂O
c. 3 MgO + 2 Fe → Fe₂O₃ + 3 Mg
d. N₂O → N₂ + O₂

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Which of the following equations are balanced? Balance those that need it. a. CaC2 + 2 H2O → Ca(OH)2 +C2H2 b. C2H8N2 + 2 N2O4 → 2 N2 + 2 CO2 + 4 H2O c. 3 MgO + 2 Fe → Fe2O3 + 3 Mg d. N2O → N2 + O2

Verified video answer for a similar problem:

Key Concepts

Chemical Equation

Balancing Equations

Stoichiometry

Which of the following equations are balanced? Balance those that need it.
a. CaC₂ + 2 H₂O → Ca(OH)₂ +C₂H₂
b. C₂H₈N₂ + 2 N₂O₄ → 2 N₂ + 2 CO₂ + 4 H₂O
c. 3 MgO + 2 Fe → Fe₂O₃ + 3 Mg
d. N₂O → N₂ + O₂