Final answer:
Understanding and balancing chemical equations is pivotal in chemistry to respect the conservation of mass and charge. Mole ratios, molar masses, and coefficients are used to relate molecules and moles to masses in reactions and to correctly balance equations ensuring that both mass and charge are conserved.
Step-by-step explanation:
The balance of chemical equations is essential in chemistry to ensure that the law of conservation of mass is satisfied. When interpreting chemical equations, it is crucial to understand that the coefficients represent mole ratios. For example, in the balanced equation of glucose combustion, we see that one molecule of glucose reacts with 6 molecules of O₂ to yield 6 molecules of CO₂ and 6 molecules of H₂O. In terms of moles, this translates to one mole of glucose reacting with 6 moles of O₂, producing 6 moles of CO₂ and 6 moles of H₂O.
For the reaction, we consider the molar masses of the substances involved to interpret the equation by masses. The given mole ratios help in calculating the actual masses using the molar masses, as in the provided example of O₂ producing 6.90 moles and equating to a mass of 221 grams, which has three significant figures. Balancing chemical equations involves not only balancing the number of atoms for each element on both sides but also ensuring that the total increase in oxidation numbers is equal to the total decrease.
To achieve this, coefficients may be used to multiply the substances in the equation, such as placing a 3 in front of CO and CO₂, and a 2 in front of Fe in one balancing scenario. This technique ensures that the equation adheres to the laws of both conservation of mass and conservation of charge.