Answer:
The answer is 465.6 mg of MgI₂ to be added.
Explanation:
We find the mole of ion I⁻ in the final solution
C = n/V -> n = C x V = 0.2577 (L) x 0.1 (mol/L) = 0.02577 mol
But in the initial solution, there was 0.087 M KI, which can be converted into mole same as above calculation, equal to 0.02242 mol.
So we need to add an addition amount of 0.02577 - 0.02242 = 0.00335 mol of I⁻. But each molecule of MgI₂ yields two ions of I⁻, so we need to divide 0.00335 by 2 to find the mole of MgI₂, which then is 0.001675 mol.
Hence, the weight of MgI₂ must be added is
Weight of MgI₂ = 0.001675 mol x 278 g/mol = 0.4656 g = 465.6 mg
To determine the time it takes to completely vaporize the given amount of water, we first determine the total heat that is being absorbed from the process. To do this, we need information on the latent heat of vaporization of water. This heat is being absorbed by the process of phase change without any change in the temperature of the system. For water, it is equal to 40.8 kJ / mol.
Total heat = 40.8 kJ / mol ( 1.50 mol ) = 61.2 kJ of heat is to be absorbed
Given the constant rate of 19.0 J/s supply of energy to the system, we determine the time as follows:
Time = 61.2 kJ ( 1000 J / 1 kJ ) / 19.0 J/s = 3221.05 s
Answer:
You will get 5.0 g of hydrogen.
Explanation:
As with any stoichiometry problem, we start with the balanced equation.
Sn
l
+
2HF
→
SnF
2
+
H
2
Moles of H
2
=
2.5
mol Sn
×
1 mol H
2
1
mol Sn
=
2.5 mol H
2
Mass of H
2
=
2.5
mol H
2
×
2.016 g H
2
1
mol H
2
=
5.0 g H
2
Answer:
Solid to liquid
Explanation:
Entropy is a state of randomness or disorderliness of the particles of a system. Some part of the heat energy of a system is related to the state of disorder or randomness of the particles of the system.
The entropic level of a system depends on two of major factors:
1. Temperature: Entropy increases with temperature rise due to the fact that the randomness of the particles of a system increases at a higher temperature.
2. Physical state of matter: The increasing order of entropy is:
Solid < Liquid < Gas
Gases are the most disordered and have the highest entropy. In moving from solid to liquid to gas, entropy of a system would increase.
