A physical exothermic process
Answer:
66.7 g
Explanation:
Number of atoms = 2×10²¹
Mass of 2×10²¹ atoms = 0.4 g
Mass of 0.5 moles of that element = ?
Solution:
1 mole contain 6.022×10²³ atoms
2×10²¹ atoms × 1 mol / 6.022×10²³ atoms
0.33×10⁻² mol
0.003 mol
0.003 mole have mass of 0.4 g
0.5 mol have mass 0.5/0.003×0.4 g = 66.7 g
Answer:
The mass of the lead
Explanation:
The 5g mass of the lead is an extensive property.
An extensive property is a physical property of matter which depends on the amount of matter that is present there in. Mass, volume e.t.c are all extensive properties. The more the quantity of the lead, the more its mass and the volume it occupies.
Melting point, boiling point, density are all intensive propeties. These properties do not rely on the amount of matter present. Any amount of lead will have the same density.
Energy released from changing the phase of a substance from the gas phase to liquid phase can be calculated by using the specific latent heat of vaporization. The heat of fusion of water at 0 degrees Celsius is 40.7 kJ/mol. Calculation are as follows:<span> </span>
Energy = 27.9 g (1 mol / 18.02 g) x 40.7 kJ/mol
Energy = 63.09 kJ
<span>362.51 Kelvin
ln (p1/p2) =( dH / R) (1/T2 - 1/T1)
ln (760 Torr /520Torr) =( 40,700 Joules / 8.314 J molâ’1K-1)(1/T2 - 1/373K)
ln (1.4615) =( 4895.35)(1/T2 - 0.002681)
0.37946 = 4895.35/T2 - (0.002681)(4895.35)
0.37946 = 4895.35/T2 - (13.124)
0.37946 + 13.124 = 4895.35/T2
13.5039 = 4895.35/T2
T2 = 4895.35 / 13.5039
T2 = 362.51
answer is 362.51 Kelvin
- 273
answer is also 89.5 Celsius</span>
