The enthalpy of the creation of Methanol is negative. This means heat is released when the reaction proceeds. You would want to use a low temperature.
Ice floats after it crystallizes because ITS DENSITY IS LESS THAN THAT OF WATER.
When a quantity of water is cools down by reducing its temperature, the molecules of the water lose kinetic energy and slow down in their movement. As the water is cooling down, it is volume is expanding. When the temperature reaches zero degree Celsius, the water becomes ice. At this point, the ice can float on water because its density is less than that of water; this is as a result of the spaces that now exist in the ice structure.
Answer: option D. The attractive forces between the sodium and chloride ions are overcome by the attractive forces between the water and the sodium and chloride ions.
Explanation:
<em>Solid sodium chloride</em> (NaCl) is a ionic compound formed by ionic bonds between by the positive, metallic cations of sodium atom, Na⁺, and the negative, non-meatllic anions of chlorine atom, Cl⁻ (chloride).
Ionic bonds, then, are the electrostatic attracion between oppositely charged particles (cations and anions).
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<em>When solid sodium chloride dissolves in water</em>, the ions (cations and anions) are separated in the solvent (water) due to the superior attracitve forces between such ions and the polar water molecules.
<em>Water</em> (H₂O) is a molecule, formed by polar covalent bonds between two hydrogen atoms and one oxygen atom.
The polarity of water molecule is due to the fact that oxygen atoms are more electronegative than hydrogen atoms, which cause that the electron density is closer to oxygen nuclei than to hydrogen nuclei. This asymmetry in the electron density conferes a partial positive charge over each hydrogen atom and a partial negative charge over the oxygen atoms.
Thus, the positively charged hydrogen atoms attract and surround the negative chloride (Cl⁻) anions, while the negatively charged oxygen atoms attract and surround the positive sodium (Na⁺) cations. It is only because the attractive forces between the water and the sodium and chloride ions are stronger than the attractive forces between the sodiium and chloride ions that such ions may be kept separated in the solution. This process is called solvation and the ions are said to be solvated by the water molecules.
Almost all properties are common to elements within a single group on the periodic table. They react with water in the same way, they have the same number of valence electrons thereby having the same valency, the number of shells in the atom of the element increases by one as we move down the group.
In general, they have the same chemical properties as chemical properties depend on the number of electrons in the valence shell i.e. the outermost shell in the atom of an element.
the answer is C. the solute polar water itself is a polar solvent so it combines well with other polar solvents (which basically have polar molecules)
