Answer :
Final answer:
The mass percent of CaCl2 in the solution made by dissolving 35.5 g of CaCl2 in 345 g of H2O is 9.3% after calculating and rounding to the correct significant figures.
Explanation:
The mass percent of CaCl2 in the solution can be calculated using the formula mass percent = (mass of the solute / (mass of the solute + mass of the solvent)) x 100%. In this case, we substitute 35.5 g for the mass of CaCl2 and 345 g for the mass of water (H2O).
Mass percent = (35.5 g / (35.5 g + 345 g)) x 100% = (35.5 g / 380.5 g) x 100% = 9.3351%. After rounding to the correct significant figures, we get 9.3%.
Therefore, the correct answer is b) 9.3%.
