The salts will be dissolved in distilled water by small quantities until the reaction reaches When ionic compounds dissolve in water, they either absorb energy from or release energy to the surroundings. If a chemical reaction absorbs heat from the surroundings, it is an endothermic reaction. If a solution releases heat to its surroundings, it is an exothermic reaction. The enthalpy of dissolution is the enthalpy change associated with the dissolution of a substance in a solvent at a constant pressure. The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies.
(h) "Hard" water contains a high concentration of calcium ions. Suggest a way to make hard water "softer: Answers: a) It could have been improved if the experimental design said " you have to place seven different nitrates in three different sodium solutions to see if a reaction occur." b) With my evidence silver nitrate was the would the cation that would make most of the anions create a precipitate. c) Chlorine can selectively remove silver ions from a solution because silver has a positive 1 charge and chlorine has a negative 1 charge so when they react it is a perfect
Part 1: Scemario 4 Carmen conducted an experiment to determine whether salt added to a cup of water affects its freezing point (the temperature at which it freezes). After some research, she hypothesized that the greater the amount of salt dissolved in the water, the lower the temperature at which the water freezes. Water samples were prepared containing equal quantities of water at the same starting temperature. Each sample received a different amount of salt and was placed into a freezer. The length of time it took for each sample to freeze was recorded as shown below.
Where did the heat the flow from (What happened to the temperature of the ice after salt was added?) 3. What is the minimum temperature that pure water can exist as a liquid at standard pressure? 4. What do you think would happen to the temperature of the ice if you added 6 tablespoons of salt instead of 2 tablespoons?
B) permanent dipoles of molecules containing covalent bonds between atoms of very different electronegativities. C) the hydrophobic effect. D) ion pairing between oppositely charged functional groups. Answer: A Page Ref: Section 5 28) The aggregation of nonpolar molecules or groups in water is thermodynamically due to the A) increased entropy of the nonpolar molecules when they associate. B) decreased enthalpy of the system.
The freezing point depression has some limitations and factors which affect to what extent the freezing point of the solvent will be decreased. One major limitation is the choice of the solute to be dissolved in the solvent because the solute must be able to dissolve sufficiently to lower the freezing point of the solvent. The solute must be soluble in the solvent in order to form a homogenous mixture. A few experiments with the unknown and different solutes will tell you what kind of properties the substance has and what substances will dissolve in it. Also, there is a limit of how much solute you can put in the solvent and you should not exceed that certain percentage.
* Water freezes at zero degrees Celsius. * Water vaporizes at a hundred degrees Celsius. Myths about Water - Drinking water will reduce blood alcohol level in your body. MYTH!
The following mistakes were made when carrying out the experiment. What effect does each have on the calculated molar mass? Be specific. For example, too large because… Only part of the pipet was immersed in the boiling water, so the temperature in part of the pipet was less than that of the water bath. If the temperature was less than the water bath in some places because only part of the pipet was immersed in the boiling water, the molar mass calculated would become lower.
* What is this substance This substance is iodide Confidence Report The aim of extraction, is to separate a part of raw material, using a solvent such as water with heat. A tincture of iodine is a common medicine sold in many pharmacies, used as an antiseptic on cuts of the skin. The objective of the seaweed lab, is to produce a tincture of iodine by extracting Iodide and other components (seen when a mixture of iodine is present), from seaweed. We
When p-xylene is mixed with another substance the freezing point lowers. When the solution reaches its freezing point it forms more of a slushy texture rather than solid like the pure p-xylene. The change in freezing point from the pure p-xylene and the unknown solution helps determine the molecular weight of the unknown. Freezing point depression shows that solutions have a higher boiling point and a lower freezing point than pure substances. 2.