Question

An aqueous NaCl solution is made using 112 g of NaCl diluted to a total solution volume of 1.00 L. Calculate the molarity, molality, and mass percent of the solution. (Assume a density of 1 08 g/mL for the solution.) An aqueous KNO_3 solution is made using 72.5 g of KNO_3 diluted to a total solution volume of 2.00 L. Calculate the molarity, molality, and mass percent of the solution. (Assume a density of 1.05 g/mL for the solution.) To what volume should you dilute 50.0 mL of a 5.00 M Kl solution so that 25.0 mL of the diluted solution contains 3.05 g of K1? To what volume should you dilute 125 mL of an 8.00 M CuCl_2 solution so that 50.0 mL of the diluted solution contains 4.67 g CuCl_2? Silver nitrate solutions are often used to plate silver onto other metals. What is the maximum amount of silver (In grams) that can be plated out of 4.8 L of an AgNO_3 solution containing 3.4% Ag by mass? Assume that the density of the solution is 1.01 g/mL. A dioxin-contaminated water source contains 0.085% dioxin by mass. How much dioxin Is present in 2.5 L of this water? Assume a density of 1.00 g/mL. A hard water sample contains 0.0085% Ca by mass (in the form of Ca^2+ ions). How much water (in grams) contains 1.2 g of Ca? (1.2 g of Ca is the recommended daily allowance of calcium for adults between 19 and 24 years old.) Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0011% Pb by mass. How much of the water (in mL) contains 150 mg of Pb? (Assume a density of 1.0 g/mL.) You can purchase nitric acid in a concentrated form that is 70.3% HNO_3 by mass and has a density of 1.41 g/mL. Describe exactly how you would prepare 1.15 L of 0.100 M HNO_3 from the concentrated solution. You can purchase hydrochloric acid in a concentrated form that is 37.0% HCI by mass and that has a density of 1.20g/mL. Describe exactly how to prepare 2.85 L of0.500 M HCI from the concentrated solution. Describe how to prepare each solution from the dry solute and the solvent. a. 1.00 times 10^2 mL of 0.500 M KCI b 1.00 times 10^2 g of 0.500 m KCI c. 1.00 times 10^g of 5.0% KCI solution by mass
Please I need help with number 54 and 61 please

Answer 1

weight of CuCl_2 = 4.67 g Volume of CuCl_2 = 50.0 mL = 0.05 L molecular weight of CuCL_2 = 134.55 g/mole moles of CuCl_2 = weight/molecular weight = 4.67 g/134.55 g/mole = 0.0347 mole concentration of CuCl_2 = moles/volume = 0.0347 mole/0.05 L = 0.694 M now, M_1 = 8 M V_1 = 125 mL M_2 = 0.694 M V_2 = ? M_1 V_1 = m_2 V_2 = V_2 = M_1 V_1/M_2 = 8 M times 125 mL/0.694 M = 1440.9 mL