Question

1. The composition of U.S. nickels is m =0.750. Ni 0.250. A nickel can be dissolved in HNOS. then converted with NH to a mixture of complex ions, in much the same way as a penny. Suppose a coin has a mass, men, of 5.000 g. What volume, V , of concentrated (i = 148 mol/L) NH, solution will be required eventually to convert all the Ni to Ni(NH)? Take Ni + 4 NH3 + 2 H20 - Ni(NH3)2+ + H2 + 2 OH as the overall equation. Follow the steps below. a. Write an expression for V, in terms of , and hy: b. Write an expression for WNH, in terms of . c. Substitute your result of part b into your equation of part a. d. Write an expression for in terms of my, and m e e. Substitute your result of part d into your equation of parte. f. Write an expression for my in terms of moon and X Ni- g. Substitute your result of part finto your equation of parte. h. Insert numbers, with their units of course, and solve.

Answer 1

n Nits Santa we know concentration & moles volume Su volume a nnu. Stolchomemc relation moles NH₂ an a 4x n I 4* not substine D Sporty mass of Ni molar mass of N) ally 2 4x mwi Xm, Ni 2 mass fraction of Ni a mass of NI Tural mass of con. so mass of m, mana sc Nix Moin Xm, nix mom Un a 4x Crno

molar mass at N 278-6934 I mot v - 4x9-250 * 5.000 38-6934 9 Imol 14-8 mol/ C To-oo576 L