Complete and balance each gas-evolution equation.

Solution: Here, we are going to calculate the percentage by mass of calcium carbonate in the given sample. Step1: Given, the volume of NaOH solution used = 11.56 mL = 11.56 / 1000 L = 0.01156 L The molarity of NaOH solution used = 1.010 M Therefore, number of moles of NaOH solution = Volume of solution in litres X Molarity = 0.01156 L X 1.010 M = 0.012 mol Step2: Again, the volume of HCl solution used = 30 mL = 30 / 1000 L = 0.030 L The molarity of HCl solution used = 1.035 M Therefore, number of moles of HCl solution = Volume of solution in litres X Molarity = 0.030 L X 1.035 M = 0.031 mol Since, 1 mole of NaOH will react with 1 mole of HCl for complete neutralisation, therefore, 0.012 mol of NaOH will react will 0.012 mol of HCl for neutralization. Thus, number of moles of HCl reacted with limestone...