Final answer:
To check if a chemical equation is balanced, compare the number of each atom on both sides of the equation. Equation a is unbalanced, while b and c are balanced. Calculate moles of reactants, compare ratios, and use these to find the limiting reactant and percent yield.
Step-by-step explanation:
To verify if a chemical equation is balanced, one must ensure that there is an equal number of atoms of each element on both sides of the equation. Looking at the reactions provided:
- a. 2 Hg(l) + O2(g) → Hg2O2 (s) - This equation is not balanced as there are 2 atoms of Hg on the left but 1 atom on the right. There are 2 atoms of oxygen on both sides, but due to the imbalance in mercury, it remains unbalanced.
- b. C2H4(g) + 2 O2(g) → 2 CO2(g) + 2 H2O(l) - This equation is balanced with 2 carbons, 4 hydrogens, and 4 oxygens on each side.
- c. Mg(NO3)2 (s) + 2 Li(s) → Mg(s) + 2 LiNO3 (s) - This equation is balanced with 1 Mg, 6 N, 6 O, and 2 Li on each side.
To determine the limiting reactant, calculate the moles of reactants and compare the ratios as per the balanced equation. The reactant that provides the lesser ratio is the limiting reactant.
For example, with a balanced equation involving ethanol and ether, convert the mass of ethanol to moles, then determine the moles of ether produced. By comparing the actual and theoretical masses, the percent yield can be calculated.