Salt lowers the freezing point and melting point of water/ice. Ice forms when water freezes and becomes 0 degree Celsius. When salt is added to ice, it dissolves into the liquid water within the ice and lowers that temperature and freezing point. “A 10-percent salt solution freezes at -6 Celsius, and a 20-percent solution freezes at -16 C.”
If one has ever watched salt melting ice, you can see the dissolving process happen, as the salt dissolves in the water and spreads out from the point first melted. Although, if the temperature of the roadway is lower than -9 Celsius or so, then the salt really won't have any affect the solid salt cannot get into the structure of the solid water to start the dissolving process.
Effect of Sand on Ice
Sand can melt ice if it is heated naturally from the sun or a warm temperature, just like all other substances that is at a higher temperature than ice. The actual texture of sand does not cause ice to melt. Sand, unless it is at a higher temperature than the ice, it would not melt.
Effect of Sugar on Ice
Fact: Sugar, and anything else that is able to dissolve in water, will melt ice. Like salt, sugar melts ice by lowering water's melting and freezing points. When sugar is added onto ice, it dissolves and interferes with the water molecules, which need to bind to ice crystals in order to freeze. Sugar’s presence needs the temperature to be much colder before the water molecules come into contact with ice crystals.
While sugar will melt ice, it still isn’t as effective as salt, which breaks down into sodium and chloride ions. When one molecule of salt dissolves, it adds two components to the solution, providing more interference in preventing water molecules from freezing.
Effect of Flour on Ice
“If you put flour in water, you make pancake batter which freezes at about the same temperature as water. So it won't melt ice at all.”
Conclusion: Sugar and salt lowers the freezing/melting pointing of water/ice,therefore making the ice melt. Although salt is more efficient when one molecule of salt dissolves,
it adds two components to the solution, providing more interference in preventing water molecules from freezing. Sand melts ice by providing traction and absorbing heat and being at a higher temperature than the ice, hence, melting it. Flour has no effect on ice, and may even serve as an insulator from the higher temperature that surrounds the ice.
Answer:
The nuclear fuel used in a nuclear reactor needs to have a higher concentration of the U 235 isotope than that which exists in natural uranium ore. U235 when concentrated (or "enriched") is fissionable in light-water reactors (the most common reactor design in the USA).
Explanation:
<span>In the question ' which of the following most likely require intermolecular force', options A and C given are definitely not the correct answers. Among the items listed in the questions, the one that will most likely required an intermolecular force is a rock maintaing its solid shape. Thus, the correct option is B. Intermolecular forces are forces which maintain chemical interactions between molecules of a particular susbstance and other types of paticles that may be present in the substance. Rocks are made up of differet particles and their structures are held together by different types of intermolecular forces depending on the types of particles present in the rock. Intermolecular forces can only occur among molecules and other particles in a compound that is why the other two options are wrong. Intermolecular force can either be attractive or repulsive. Attraction occurs between molecules of opposite charges, that is, positive and negative charges while repulsion occurs between particles of like charges, for intstance, between positive and positive charges. The Intermolecular forces that exist in a compound maintaings the integrity of the structure of that compound. Intermolecular forces in compounds exist in different forms, we have electrovalent bonds, covalent bonds, hydrogen bond, vander waals forces, etc. The type of molecules that exist in a compound will determine the type of intermolecular forces that will exist among the molecules of that substance. Electrovalent bonds are the strongest type of intermolecular force and it normally exist between metals and non metals. Covalent bonds involved sharing of electrons among the participating elements while vander waals forces are the weakest form of intermolecular forces. Forces are often required to break intermolecular forces apart. Breaking the intermolecular forces apart will destroy the structure of the substance inlvolved.</span>
Answer #1 is "there is 2.5 grams of solute in every 100 g of solution."
We calculate for 2.5% by mass solution by dividing the mass of the solute by the mass of the solution and then multiply by 100.
Answer #2 is "that mass ratio would be 2.5/100 or 2.5 grams of solute/100 grams of solution."
We weigh out 2.5 grams of solute and then add 97.5 grams of solvent to make a total of 100 gram solution, that is,
mass of solute / mass of solution = 2.5g solute / (2.5g solute + 97.5g solvent)
= 2.5g solute / 100g solution
Answer#3 is "a solution mass of 1 kg is 10 times greater than 100 g, thus one kilogram (1 kg) of a 2.5% ki solution would contain 25 grams of ki."
We multiply 10 to each mass so that 100 grams becomes 1000grams since 1000 grams is equal to 1 kg:
mass of solute / mass of solution = 2.5g*10/[(2.5g*10) + (97.5g*10)]
= 25g solute/(25g solute + 975g solvent)
= 25g solute/1000g solution
= 25g solute/1kg solution
Not exactly chemistry but ok.
Phó is one of the famous dish in Vietnamese Culture
Hence, the answer is Vietnamese Cuisine
