Question

QUESTION 1 0.5 points Save Answer The weak acid, HX, is neutralized by sodium hydroxide as shown below: HXiaq) + NaOH(ac) + NaCN aql + H200). Suppose you carried out this reaction in a coffee cup calorimeter using 50.0 mL of 0.500 M HX and 0.500 mL of 0.500 M NAOH If the temperature of the calorimeter increases by 1.4°C, what is the enthalpy of this neutralization reaction (in kJ/mol? Assume the density of the solution is 1.00g/mL and that the specific heat is 4.184 J/g "C [Enter your value with the appropriate sign and value, but no units. QUESTION 2 0.5 points Save Answer Colorless gas nitric oxide gas, NO, can react with oxyger to form the brown gas nitrogen dioxide, No2, as shown below: 2 NO(g) + O2lg) - 2 NO2lg- Suppose you wanted to carry out this reaction in the laboratory. You could filled one gas syringe with 100 ml of nitric oxide and another with 156. mL of oxygen gas. When you connected the syringes and mixed the gases, the reaction mixture changes to a brown color indicating the the reaction had occurred. If the syringes were maintained at constant temperature and pressure, what would be the expected volume of the reaction mixture after the reaction? Hint 1: It is not simply 100+156 mL. Hint 2: nitric oxide is the limiting reagent, which means the end result is a combination of the product gas and the leftover oxygen gas. QUESTION 3 0.5 points Save Answer If nitrogen gas has a density of 1.14 g/L, and an unknown gas has a density of 1.28 at the same temperature and pressure, what is the ratio of the rate of effusion of the known gas to the rate of effusion of nitrogen?

Answer 1

Page- Questian 1 Moles dHX taken 0.500 mol x 50.0 mL = 0.025 mol 000 mL Moles dr NaoH taken= 0.500mol X 0.500 mL 2.5x1o mol 1000 mL From the neacticn stoichiomelry, we can see that 2.5x1o ' mol Naot wil neaut witt 2.5 xlo mol HX, a» NaOt i imtng nayeut ene Nat, as tie tempenatune d calonimetey has incneased, the neutralization neauticu i exotienusic and the entialpy will have negalive ign Naw, magnititude d heat evolved dsolnxVsolu) xCsolu x4T X J .00 50.00.500) mĽ X 4,184 = 295.8 J 3 (1J- 0.2958 kU 0.2958 kJ Megnithe d enitalp 83.2 kJ/mo) 25x1 mo ANSOER 1183.2

e-2 Question 2 2NO ()02(a)- 2N0 (a) At cowtant tempenatuie a pressuie, moles dy a gas Popontionel to ilo voluue As nitic oxide is the limiting necgent, neaction ill tale place such that cll nitic oxide ill qot cousumed. om necalion loichiomelyy, nitnic oxide will neact wit ihe amount which in halt d ivolume (as mole a volume одем to So, to0 mL nitnie oside oill neat wih 50 mL oxygen dioxide. nitrogen Produce 100 mL Volume d neaction mixture atter eution volume d prdut volume d lettover oew gs 00 mL156-50 mL = 206 mL ANSWER 206 mL

page-3 Question 3 At scme tempenatune ad pnessune , we have 1 নন whene, nnate dr etbuniow d deity d the gas Tunknoon dnitogen dumkuron 14 0.95 itrogen ,26 0.951 1 ANSWER