question archive A mixture of oxygen and krypton gases, in a 6
Subject:ChemistryPrice:2.84 Bought3
A mixture of oxygen and krypton gases, in a 6.19 L flask at 19 °C, contains 1.92 grams of oxygen and 17.9 grams of krypton. The partial pressure of krypton in the flask is atm and the total pressure in the flask is atm
A mixture of hydrogen and nitrogen gases is maintained in a 7.04 L flask at a pressure of 3.37 atm and a temperature of 82 °C. If the gas mixture contains 0.724 grams of hydrogen, the number of grams of nitrogen in the mixture is g
The following information is given for n-pentane, C5H12, at 1atm:
boiling point = 36.2 °CHvap(36.2 °C) = 25.8 kJ/molspecific heat liquid = 2.28 J/g°C
At a pressure of 1 atm, what is H in kJ for the process of condensing a 36.7 g sample of gaseous n-pentane at its normal boiling point of 36.2 °C.
kJ
The following information is given for n-pentane, C5H12, at 1atm:
boiling point = 36.2 °CHvap(36.2 °C) = 25.8 kJ/molspecific heat liquid = 2.28 J/g°C
At a pressure of 1 atm, kJ of heat are needed to vaporize a 28.5 g sample of liquid n-pentane at its normal boiling point of 36.2 °C.
The following information is given for mercury at 1atm:
boiling point = 357 °C
Hvap(357 °C) = 59.3 kJ/mol
melting point = -39 °C
Hfus(-39 °C) = 2.33 kJ/mol
specific heat solid= 0.141 J/g°Cs
specific heat liquid = 0.139 J/g°C
What is H in kJ for the process of freezing a 31.3 g sample of liquid mercury at its normal melting point of -39 °C.
kJ
The following information is given for silicon at 1atm:
boiling point = 2355 °C
Hvap(2355 °C) = 297 kJ/mol
melting point = 1410 °C
Hfus(1410 °C) = 46.4 kJ/mol
specific heat solid= 0.711 J/g°Cs
pecific heat liquid = 0.908 J/g°C
kJ are required to melt a 39.3 g sample of solid silicon, Si, at its normal melting point.
1) total pressure, P= nRT/V= 0.334*0.082*292/6.19=1.292 atm
partial pressure of Kr = 0.214*0.082*292/6.19= 0.828 atm
2)mass of N2= 0.457 *14.007= 6.401 g
3)heat required= 13.125 kJ
4)0.3636 kJ
5)64.927 kJ
Step-by-step explanation
1) 1.92 grams of oxygen = 1.92/16 = 0.12 moles
17.9 grams of krypton = 17.9/83.798= 0.214 moles
total mole= 0.120 + 0.214= 0.334 moles
temperature= 19+273= 292 K
volume= 6.19 L
total pressure, P= nRT/V= 0.334*0.082*292/6.19=1.292 atm
partial pressure of Kr = 0.214*0.082*292/6.19= 0.828 atm
2)V=7.04 L
P=3.37 atm
T=82+273= 355 K
n= PV/RT= 3.37*7.04/0.082*355=0.815 moles
moles of H2= 0.724/2.02= 0.358 moles
moles of N2= 0.815- 0.358= 0.457 moles
mass of N2= 0.457 *14.007= 6.401 g
3)Hvap(36.2 °C) = 25.8 kJ/mol
36.7 g sample of gaseous n-pentane= 36.7/72.15= 0.5087 moles
heat required= 25.8*0.5087= 13.125 kJ
4)31.3 g sample of liquid mercury = 31.3/200.59= 0.1560 moles
Hfus(-39 °C) = 2.33 kJ/mol
Heat= 2.33*0.1560= 0.3636 kJ
5)Hfus(1410 °C) = 46.4 kJ/mol
39.3 g sample of solid silicon= 39.3/28.0855= 1.3993 mole
heat= 46.4*1.3993= 64.927 kJ