Two new metallic elements have been discovered, Cimium (Ci) and Sadowium (Sd). Both the pure elements and their solutions form simple cubic lattices. The bond strengths of the Ci-Ci and Sd-Sd bonds are known, but not the Ci-Sd bond.

Bond Bond Energy (kJ/mole)
Ci-Ci -245
Sd-Sd -191
J-R ??

Mixing a solution of 40% cimium and 60% sadowium is an endothermic process. According to your calorimeter, the solution draws 44.6 kJ/mol of heat when mixed. What is the strength of the Ci-Sd bond? Please give your answer in kJ/mol.

Any ideas??

Anonymous, your solution is wrong. Could you give me a hint of your steps?

whats the answer

Use the equation:

delta(w)= 2w(A-B)-w(A-A)-w(B-B)

delta(w)= 44.6
(A-A)Ci-Ci=-245
(B-B)Sd-Sd=-191

44.6 = 2w(A-B)-(-245)-(-191)
w(A-B) = [44.6 - 245 - 191]/2
w(A-B)= -195.7

-195.7

its -195.7

To find the strength of the Ci-Sd bond, we need to calculate the energy change associated with the formation of the solution. We can use the concept of lattice energy to determine this value.

Lattice energy is the energy required to completely separate one mole of a solid ionic compound into its gaseous ions. In this case, we have metallic elements, but we can consider their bonds as ionic bonds for simplification.

The total energy change for the formation of the solution is given by the sum of the energy required to break the Ci-Ci and Sd-Sd bonds and the energy released when the Ci-Sd bond is formed:

Total energy change = (Energy to break Ci-Ci bonds) + (Energy to break Sd-Sd bonds) + (Energy released when Ci-Sd bond is formed)

Since the bond strengths of Ci-Ci and Sd-Sd are known, we can substitute these values into the equation:

Total energy change = (-245 kJ/mol) + (-191 kJ/mol) + (Energy released when Ci-Sd bond is formed)

The energy released when the Ci-Sd bond is formed can be represented as J-R.

Total energy change = -245 kJ/mol - 191 kJ/mol + J-R

Now, we know from the calorimeter that the solution draws 44.6 kJ/mol of heat when mixed. This heat absorption is an endothermic process, meaning the reaction absorbs energy from the surroundings. Therefore, the total energy change for the formation of the solution is positive:

Total energy change = +44.6 kJ/mol

Now, equating the total energy change equations, we have:

-245 kJ/mol - 191 kJ/mol + J-R = +44.6 kJ/mol

To find J-R, we can rearrange the equation:

J-R = +44.6 kJ/mol + 245 kJ/mol + 191 kJ/mol
= +480.6 kJ/mol

Therefore, the strength of the Ci-Sd bond is +480.6 kJ/mol.