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Nitrogen-13 has a half-life of 9.97 minutes. How much of a 10.0-g sample remains after 60.0 minutes?

What is the equilibrium pH of an initially 0.26 M solution of the monoprotic acid hydrazoic acid (HN3) at 25°C (Ka = )?

Calculate E for the following electrochemical cell at 25ºC,Cu | Cu2+ (0.100 M) || Zn2+ (0.0750 M) | Znif Eº (Cu2+) = +0.339 V and Eº (Zn2+) = -0.762 V. (R = 8.31 J/K·mol, F = 96480 C/mol e-)

Carbonyl bromide decomposes to carbon monoxide and bromine.COBr2(g) D CO(g) + Br2(g)Kc is 0.19 at 73 °C. If an initial concentration of 0.63 M COBr2 is allowed to equilibrate, what are the equilibrium concentrations of COBr2, CO, and Br2?

Al3+ is reduced to Al(s) at an electrode surface. If a current of 25 amperes is maintained for 8.0 hours, what mass of aluminum is deposited on the electrode? Assume 100% current efficiency.

At 25 °C, what is the osmotic pressure of 8.65 g urea (CON2H4) diluted with water to 1.50 L? (R = 0.08206 L·atm/mol·K)

The equilibrium constant for a reaction at 25 °C is 4.7 ´ 10-8. What is DG°? (R = 8.314 J/K·mol)

Calculate for the reaction below at 25.0 °C2 H2O(g) + S(s) ® 2 H2S(g) + O2(g)given = +442.4 kJ and = +206.9 J/K.

The thermochemical equation for the formation of ammonia from elemental nitrogen and hydrogen is as follows.N2(g) + 3 H2(g) D 2 NH3(g)  DH = -92.2 kJWhich of the following will drive the equilibrium system to the right?

A gaseous mixture of NO2 and N2O4 is in equilibrium. If the concentration of N2O4 is 7.1 ´ 10-4 M, what is the concentration of NO2?2 NO2(g) D N2O4(g)  Kc = 170