According to Science Kids, things dissolve faster in hot water because the molecules in hot water move at a greater speed, bumping more frequently against the solute (the item being dissolved). The more frequent bumping against the solute causes it to dissolve quicker in the water.Know More
Hot water has a higher amount of kinetic energy. The increased amount of kinetic energy is what causes the molecules to move faster. A solvent (the item that the solute is dissolved into) dissolves the solute by breaking up both its molecular bonds and the solute's molecular bonds. The molecular bonds in both substances have to be broken so that new molecular bonds can form between the solute and solvent. Once the solvent and solute are combined with molecular bonds, it is known as a solution.
The amount of energy required to dissolve a solute into a solvent depends on what substance the solute is. Solutes with strong molecular bonds require more energy for the bonds to be broken. Weak solutes can dissolve at a lower temperature than strong solutes.
Solutes that do not dissolve in water have nonpolar covalent bonds. Nonpolar covalent bonds have a low electronegativity (tendency to attract electrons) and do not readily form new molecules. Water is a polar molecule that requires another polar molecule to form a new molecule.Learn more about Solutions & Mixtures
Warm, but not hot water (between room temperature and 100 degrees fahrenheit) can be used to dissolve yeast; chefs should be careful to avoid adding too-hot or too-cold water, or the yeast could either remain dormant or die and fail to cause rising. Dissolving yeast in warm water is a way to wake and activate the yeast before it's added to dough.Full Answer >
Since non-polar substances are held together by weak van der Waals interactions and water molecules use strong hydrogen bonds, the van der Waal interactions of non-polar substances are not strong enough to break the hydrogen bonds of the water molecules. Accordingly, the non-polar substance cannot disperse itself in water.Full Answer >
According to the Purdue University College of Science, sugar dissolves easily in water due to the fact that sucrose molecules are held together with weak intermolecular forces. The energy produced when these molecules bond with water is more than enough to offset the energy needed to break those bonds in the first place.Full Answer >
Sugar water freezes faster than salt water, because salt has more molecules than sugar. Normally, water freezes at 32°F, however, when a substance is added to the water, it lowers its freezing point. This is not because of the chemical nature of the substance being added, but rather the number of molecules. This is referred to as a colligative property.Full Answer >