Answer:
XY would have a higher melting point than NaCl.
Explanation:
The electrostatic force (F) between ions in an ionic lattice can be estimated using Coulomb's Law.
where,
k is the Coulomb's constant
q₁ and q₂ are the charges of the ions
r is the distance between the ions
X⁺⁺ and Y⁻⁻ are doubly charged with respect to Na⁺ and Cl⁻ so the force between them is 4 times the force between Na⁺ and Cl⁻. Since the force is stronger, it would require more energy to break it to take it to the liquid state, so a higher melting point is expected.
Answer:
Cleaning up oil spills and metal contaminates in a low-impact, sustainable and inexpensive manner remains a challenge for companies and governments globally.
But a group of researchers at UW–Madison is examining alternative materials that can be modified to absorb oil and chemicals. If further developed, the technology may offer a cheaper and “greener” method to absorb oil and heavy metals from water and other surfaces.
Aerogels, which are highly porous materials and the lightest solids in existence, are already used in a variety of applications, ranging from insulation and aerospace materials to thickening agents in paints. The aerogel prepared in Gong’s lab is made of cellulose nanofibrils (sustainable wood-based materials) and an environmentally friendly polymer. Furthermore, these cellulose-based aerogels are made using an environmentally friendly freeze-drying process without the use of organic solvents.
It’s the combination of this “greener"material and its high performance that got Gong’s attention.
“For this material, one unique property is that it has superior absorbing ability for organic solvents — up to nearly 100 times its own weight,” she says. “It also has strong absorbing ability for metal ions.”
Treating the cellulose-based aerogel with specific types of silane after it is made through the freeze-drying process is a key step that gives the aerogel its water-repelling and oil-absorbing properties.
<u>Answer: </u>The concentration of 
in the solution is 
<u>Explanation:</u>
pH is defined as the negative logarithm of hydrogen ion concentration present in the solution.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
.....(1)
We are given:
pH of solution = 2.5
Putting values in equation 1, we get:
![2.5=-\log [H^+]](https://tex.z-dn.net/?f=2.5%3D-%5Clog%20%5BH%5E%2B%5D)
![[H^+]=10^{-2.5}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-2.5%7D)
![[H^+]=3.16\times 10^{-3}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D3.16%5Ctimes%2010%5E%7B-3%7DM)
Hence, the concentration of in the solution is
Endothermic- endothermal, heat absorbing
Ectothermic- exothermal exoergic energy releasing, heat releasing
