Question

Question 7 (1 mark) Consider the reaction between aqueous sodium hydroxide and silver cation: 2 NaOH (aq) + 2 Ag+ (aq) → Ag20 (s) + H20 (1) + 2 Na+ (aq) a) Given the data in the table below, calculate the standard enthalpy change (in kJ) for the reaction. Compound Ag+ (aq) Ag20 (s) H2O (1) Na+ (aq) NaOH (aq) A/H (kJ/mol) 100.0 - 50.0 - 275.0 - 250.0 -475.0 b) When the reaction was performed in a constant pressure calorimeter, it was observed that the temperature of the solution rose from 25.0°C to 35.0 °C. If there was 150.0 g of solution in the calorimeter, calculate the mass of sodium hydroxide used in this experiment. You may need to obtain some data from your textbook when answering this question. . Assume the specific heat capacity of the solution is the same as the specific heat capacity of water. a) standard enthalpy change for the reaction: b) mass of sodium hydroxide used:

Answer 1

7-9 2 NaOH ag + 2 Agrag A9₂06) + H20W) + 2 Natas) 2 mole 1 Naf 22 O Hºran - A Hopeondue - A Hireactant) A Ho Product = DH° Aq06, + AHO 4300 + ( Ho Na (ag, ) & 2 =mle 50 kJ/mo))+(-275x3]mal) 7 (-2.501kr = – 0 2 5 kJ AHO reactant = 2 mol H²NaO Higgl + Ho Ag caal) ) x2 mor = 2 mol (-475 KJ) + 2 mal (100 kand mol = -950 kJ + 200 kJ = – 750 KS Hran = DH Product - Horeactout = -025 KJ - (-750 kJ) = – 825kJ + 750 kJ = - 75 kJ

of Heat required to raise temperature solution from 250 c to 35°c - Q = cpmot 1(cp=mat) Jep= specificheat goc - 4.2 J x 150 x 100 = 4.251900 pa Im = mass of solution - 6300 5 TATE 35°C-25°c=10°c = 6.3 kJ from result ad @ 75 kJ heat produced an, when a mol NaOH Taken then 6.3 k5 u 1. - 2 mol x 6.3 kJ TEKS =.168 mole MaOH mass of sod. Hydwxide = mole x molarmas = 168 mole x 40g/mol F 6.72 gm NaOH) Ans