Balanced Chemical Equation Practice Quiz

2H2 + O2 �' 2H2O is balanced because there are 4 hydrogen atoms and 2 oxygen atoms on both sides of the equation. This demonstrates the law of conservation of mass.

The main focus when balancing a chemical equation is to equalize the number of atoms for each element on both sides. This ensures that the conservation of mass is maintained throughout the reaction.

A balanced chemical equation shows that the mass remains constant during a chemical reaction. This reflects the law of conservation of mass by ensuring that the total number of atoms for each element is the same on both sides.

Since chlorine exists as Cl2 with two atoms and each NaCl contains one chlorine atom, a coefficient of 2 is needed to provide the correct number of chlorine atoms on the product side. This balances the equation according to the law of conservation of mass.

Balancing chemical equations is essential because it guarantees that the number of atoms remains the same on both sides of the equation, honoring the law of conservation of mass. This step is fundamental for accurate stoichiometric calculations in any chemical reaction.

Option A reflects the correct stoichiometry for the combustion of propane, where the number of carbon, hydrogen, and oxygen atoms are balanced on both sides. The coefficients ensure complete combustion with the appropriate amounts of oxygen.

The molecular equation AgNO3 + NaCl �' AgCl + NaNO3 is balanced as written because each element appears in equal amounts on both sides of the reaction. No additional coefficients are needed to satisfy the conservation of mass.

A stoichiometric coefficient specifies the relative number of moles of each substance involved in a chemical reaction. This coefficient is essential for converting between amounts of reactants and products.

Option A correctly balances the reaction by accounting for 4 iron atoms and 6 oxygen atoms on both sides of the equation. The use of appropriate coefficients ensures that the law of conservation of mass is satisfied.

The balanced equation shows that potassium, chlorine, and oxygen are all conserved with equal numbers on both sides. This complete balance confirms that the stoichiometric coefficients are correct.

Splitting a redox reaction into half-reactions simplifies the balancing process by allowing the independent balancing of both mass and charge. This makes it easier to correctly combine the oxidation and reduction components of the reaction.

The equation N2 + 3H2 �' 2NH3 correctly represents the synthesis of ammonia by balancing both the nitrogen and hydrogen atoms. It is the standard form of the Haber process equation.

The reaction Zn + 2HCl �' ZnCl2 + H2 is already balanced, with one zinc, two chlorine, and two hydrogen atoms on both sides. This satisfies the principle of conservation of mass without any further adjustment.

Option A is balanced because 2 moles of KClO3 yield 2 moles of KCl and 3 moles of O2, ensuring that potassium, chlorine, and oxygen atoms are equally distributed on both sides. This is essential for maintaining mass conservation.

A net ionic equation simplifies the full ionic equation by including only the species that undergo a chemical change. This omission of spectator ions helps focus on the actual reaction taking place.

Option A correctly balances the combustion of ethanol by ensuring that carbon, hydrogen, and oxygen atoms are equal on both sides of the equation. The coefficients reflect the proper allocation of oxygen from both ethanol and O2.

Option A is the correctly balanced net ionic equation in an acidic medium, accounting for the electrons, protons, and water molecules required to balance both mass and charge in this redox reaction. It accurately represents the stoichiometry between the permanganate ion, iron(II), and protons.

Option A correctly balances the equation by ensuring that 4 aluminum atoms and 6 oxygen atoms appear on both sides. The use of appropriate coefficients guarantees that the law of conservation of mass is upheld.

Option A correctly reflects the stoichiometry needed to form calcium phosphate by balancing both the number of calcium and phosphate ions. This equation maintains charge balance and ensures proper formation of Ca3(PO4)2.

Option A balances the acid-base reaction by ensuring that two sodium ions are available to form Na2SO4 and that the water molecules are produced in the correct proportion. This alignment of coefficients fulfills the stoichiometric requirements for complete neutralization.