Question

A helium-filled balloon at 320.0 K and 1 atm, contains 0.25 g He, and has a volume of 1.23 L. It is placed in a freezer (T = 240.0 K), and its volume decreases to 1.06 L. Find ΔE for the gas (in joules). (C_p of He = 20.8 J/mol K.)

A: -59.79

B: -86.70

C: -125.71

D: -182.28

E: -264.31

F: -383.24

G: -555.70

H: -805.77

Given that the ΔH^o_rxn = -2842.0 kJ, for the following reaction:

2C₃H₅(NO₃)₃(l) → 6CO₂(g) + 1/2O₂(g) + 3N₂(g) + 5H₂O(g)

determine the standard enthalpy of formation, ΔH^o_f, for: C₃H₅(NO₃)₃(l)(nitroglycerin). Enter in kJ/mol.

A: -193.554872494167

B: -226.459200818175

C: -264.957264957265

D: -310

E: -362.7

F: -424.359

G: -496.50003

H: -580.9050351

Answer 1

1) 2 1.234 T, 320.0k V2 = 1.06L Ta : N2 T, 1.0643 20.0 1.23 : 275.77K AT = 320-275.77 44.23 K massa (m): 0.25k cp 20.8 J/molok molar mass of Her 4.0 g/mol .. moles of He (= mass molar mais 0. 25 mol 4.0 LE = - mcpaT - - 0.25 x20.8 x 44, 23 T 4.0 . -58.01 ) A is the closest answer.

Comment if any problem

Please post each question separately