Which one has the greater lattice energy?
Cynic, The lattice energy of salts is proportional to the charges on the ions divided by the distance between the nuclei: E = -C* Z+Z-/r (where C is a constant, Z+ is the charge on the cation, Z- is the charge ion the anion, and r is the distance between the nuclei). From a 30,000 ft view, the highere the charge on the ions, and the smaller they are, the higher the lattic energy. Therefore, (1) oxides will have higher lattice energies than chlorides, and (2) beryllium salts will generally have higher lattice energies than calcium. Your answer is BeO. On-line thermodynamic data (just to ice it!) BeO: 4443 kJ mol-1 CaO: 3401 kJ mol-1 BeCl2: 3020 kJ mol-1 CaCl2: 2258 kJ mol-1 Hope that helped!
Is the lattice energy for the salt greater or less than the hydration energy for the salt?
a. The lattice energy is less than the hydration energy. The lattice energy is the energy needed to break down the lattice in the water and is endothermic (takes in heat), while the hydration energy is the energy released when the ions are surrounded by water molecules and is exothermic (releases heat). As the temperature has risen, the hydration energy must be greater as more energy has been released than taken in during the process. b. The solubility will increase as temperature increases as the system has higher energy and so the lattice energy is easier overcome and the salt more easily broken down to dissolve.
Why hydration energy should be greater than lattice energy for solubility?
This is because hydration enthalpy favors solubility while lattice enthalpy favours the crystalline nature of ionic compounds.
Ionic substance whose lattice energy is greater than its hydration energy.?
Oh how I wish I could answer that. My physics class was way too long ago.
Is there any exception in the trend of lattice energy and hydration energy?
Trends in Alkali metalsHydration enthalpy of alkali metals:The extent of hydration depends upon the size of the ions.Smaller the size of the ion, greater is the hydration enthalpy.Li+> Na+> K+> Rb+> Cs+Lattice energy of alkali metals:The lattice energy decreases with the increase in the size of the cation i.e. from Li+to Cs+Trends in Alkaline earth metalsHydration enthalpy of alkaline earth metals:The hydration enthalpy becomes smaller as the size of the ion increases.Be+2> Mg+2> Ca+2> Sr+2> Ba+2Lattice energy of alkaline earth metals:Lattice energy is directly proportional to charge and inversely proportional to the size.On moving down the group, the metal ions increase in size and the lattice enthalpy decrease.
What is an ionic substance whose lattice energy is greater than its hydration energy?
Sorry, but there are plenty of compounds like this that are soluble. So insoluble is not the right answer. DeltaH of solution = - DeltaH lattice + DeltaH hydration. So if the lattice energy (energy about the same as enthalpy in this case) is > hydration energy, the heat of solution will be positive, or endothermic. DeltaH lattice is always negative, and DeltaH hydration is also always negative, so the sign of DeltaH of solution works out as I stated. There are a few compounds with an endothermic heat of solution. One that finds use in cold packs is ammoniuim nitrate, NH4NO3.
What is the difference between lattice energy and hydration energy? How can we find hydration energy?
This is one concept where students are usually confused .I will try to make it simple. Lattice energy is the amount of energy required to break one mole of crystal lattice into its constituent ions. Ionic compounds are crystalline in nature. They are formed between two elements from two different blocks.E.g.NaCl Sodium belongs to 1 group of s block and Cl belongs to 17 group of p block. There is a lot of difference in the energies of electrons of these two elements as they belong to different valence shell, but these elements form ions and result in strong ionic bonding. During the formation of ionic bond some amount of energy is released and forms a crystal lattice. Lower the energy , higher is the stability. Every bond formation always results in decrease of energy. During ionic bond formation more amount of energy is released. Hence it is most stable bonding. This released energy is called as Lattice energy. Lattice energy is also defined as the amount of energy released from the constituent ions to form one mole of crystal lattice. The same amount of energy is used to break the crystal lattice into constituent ions. Hydration energy is the amount of energy released to break one mole of crystal lattice into its constituent ions in water. The required energy is provided by water hence the lattice energy is called as hydration energy else if any other solvent used then it is solvation energy.Hydration energy can be calculated using Born Haber Cycle.
What is the lattice energy of RbCl? Is this value greater or less than that of NaCl?
The lattice energy of Rubidium Chloride 689 kj/mol, while Sodium Chloride has a lattice energy of 787 kj/mol. Lattice energy is dependent on two things; 1) The charge of the species and 2) The distance between them. In this case both Sodium and Rubidium have the same charge, but Rubidium is much larger than Sodium, so it packs less efficiently than Sodium, which means that it will be further away from each of the Chlorides, thus making it have a reduced lattice energy.
What is the lattice energy of RbCl? Is this value greater or less than that of NaCl?
I don't feel like fetching my chem book at the moment, but I do believe it's RbCl2. If you don't get a correct-sounding answer, I'll look it up the lattice energy for you if it's available. If it's not in my chem book I can get it out of the CRC manual on Monday. My email is briankey75@yahoo.com