How to Balance Chemical Equations
One of the most important skills in this chapter is balancing chemical equations. A balanced chemical equation shows that the law of conservation of mass is obeyed, meaning that the number of atoms of each element is the same on both sides of the equation. To balance a chemical equation, you need to follow these steps:
mastering chemistry homework answers chapter 3
Write the unbalanced equation, making sure the formulas for all substances are correct.
Find coefficients to balance the equation by starting with the most complex substance and considering one element at a time. A coefficient is a number that is placed in front of a formula to indicate how many moles of that substance are involved in the reaction.
Check that the equation is balanced by counting the number of atoms of each element on both sides of the equation.
If necessary, simplify the equation by dividing all coefficients by a common factor.
For example, lets balance the following equation:
C_2H_6 + O_2 -> CO_2 + H_2O
Step 1: Write the unbalanced equation.
C_2H_6 + O_2 -> CO_2 + H_2O
Step 2: Find coefficients to balance the equation. We can start with carbon, since it appears only once on each side. There are two carbon atoms on the left side and one on the right side, so we can balance them by adding a coefficient of 2 to CO_2.
C_2H_6 + O_2 -> 2CO_2 + H_2O
Next, we can balance hydrogen, since it also appears only once on each side. There are six hydrogen atoms on the left side and two on the right side, so we can balance them by adding a coefficient of 3 to H_2O.
C_2H_6 + O_2 -> 2CO_2 + 3H_2O
Finally, we can balance oxygen, since it appears twice on each side. There are two oxygen atoms on the left side and seven on the right side, so we can balance them by adding a coefficient of 7/2 to O_2. However, since we usually avoid fractional coefficients, we can multiply all coefficients by 2 to get rid of the fraction.
2C_2H_6 + 7O_2 -> 4CO_2 + 6H_2O
Step 3: Check that the equation is balanced. We can count the number of atoms of each element on both sides and see that they are equal.
Left: C = 4; H = 12; O = 14
Right: C = 4; H = 12; O = 14
Step 4: Simplify the equation if possible. In this case, there is no common factor that can divide all coefficients, so we cannot simplify further.
The final balanced equation is:
2C_2H_6 + 7O_2 -> 4CO_2 + 6H_2O
How to Perform Mole Conversions
A mole is a unit that represents a specific number of particles, such as atoms, molecules, ions, or electrons. The number is called Avogadros constant and it is equal to 6.022 x 10^23. Mole conversions are calculations that allow us to convert between different units of measurement using moles as an intermediate step. Some common units that we can convert using moles are c481cea774
