Chapter 3
Q. 3.8
Crystals of sodium hydroxide (lye) react with carbon dioxide from air to form a colorless liquid, water, and a white powder, sodium carbonate, which is commonly
added to detergents as a softening agent. Write a balanced equation for this chemical reaction.
STRATEGY
1. Translate names to formulas and write a “skeleton” equation. Recall the discussion in Sections 2.6 and 2.7.
2. Write the physical states.
3. Balance by starting with an element that appears only once on each side of the equation.
4. Check that you have the same number of atoms of each element on both sides of the equation.
Step-by-Step
Verified Solution
| NaOH + CO_{2} → Na_{2}CO_{3} + H_{2}O | 1. Skeleton equation |
| NaOH(s) + CO_{2}(g) → Na_{2}CO_{3}(s) + H_{2}O(l) | 2. Physical states |
| 2NaOH(s) + CO_{2}(g) → Na_{2}CO_{3}(s) + H_{2}O(l) | 3. Balance |
| 2 on left 2 on right
1 on left 1 on right 2 on left 2 on right 2 + 2 = 4 on left 3 + 1 = 4 on right The balanced equation is 2NaOH(s) + CO_{2}(g) → Na_{2}CO_{3}(s) + H_{2}O(l) |
4. Check H
Check C Check Na Check O |