Hydrates are crystal solids and water. 2. In order to determine the percent composition and the empirical formula of a hydrate, you must know how much water is in the hydrate. As you cannot measure the mass of the water as it gets added to the salt, how can you determine this? By dehydrating it using fire.
There will have some error. 2) A volatile liquid was allowed to evaporate in a 43.298 g flask that has a total volume of 252 ml. the temperature of the water bath was 100˚C at the atmospheric pressure of 776 torr. The mass of the flask and condensed vapor was 44.173 g. calculate the molar mass of the liquid. T = 273 + 100 = 373 V = 252 mL = 1 L / 1000 mL = 0.252 L P = 776 Torr R= 0.0821 mass of 44.173 - 43.298 g = 0.875g moles of gas = PV / RT = 776 x .252 / 62.363 x (273+100) =0.00841 moles molar mass = 0.875g / 0.00841 moles = 104.1 g/
Data: Data Table 1 | | | Rubbing Alcohol Trial # | Boiling Point | Percent Error | 1 | 79.5 C | 3.52% | 2 | 84.0 C | 1.90% | 3 | 83.5 C | 1.30% | Data Table 2 | | | | Acetamide Trial # | Melting Point | Freezing Point | Percent Error (Melting Point) | 1 | 79.5 C | 57.5 C | 3.50% | 2 | 80.5 C | 59.5 C | 0.60% | 3 | 78.0 C | 61.0 C | 3.70% | Observations: It was observed that thermometer placement could affect the readings in the water bath. I ended up holding the test tube assembly to where the bottom of the test tube was not touching the bottom of the beaker to ensure better readings. Also, when substances recrystallize, I am not sure whether to take a reading when the substance has full crystallized or begun to so results could be fairly inaccurate. Questions: A. Why is it useful
For part 2, do the same thing as part 1 except use an unknown hydrate and calculate the percent mass of water in an unknown hydrate. Observations Part 1 At first the hydrate was a crystal red color. When it was placed on the hot plate and its state changed it began to change color. As it heated it started to become liquidly and bluish in color. Once it cooled down it became a purplish black color.
Tap water is considered homogenous because it often contains dissolved minerals and gasses which are dissolved throughout the water. 4. Is isopropyl alcohol (rubbing alcohol) a heterogeneous or homogenous mixture? Explain your answer. Rubbing alcohol is a hemogenous since you can’t see the different parts in it.
The tip of the inner blue flame is the hottest portion. 4. How will you know in this experiment when the hydrate BaCl2*2H20 has been completely dehydrated? It will be completely dehydrated when the difference in successive weights of the crucible, cover, and residue (after cooled to room temp.) is 0.0020 g or less.
hoSpecific heat capacity in liquids Specific heat capacity in liquids How do liquid filled radiators work and what are the useful properties of these liquids? Liquid-filled electric radiators are sealed units that have an internal heating element that releases heat through the outer case; however the elements are put in a liquid such as: oil, water or heat transfer agent. Depending on the design of the radiator, the heat generated can be through radiation or a combination of radiation and convection (1). (10) (10) The liquid used is anti-freeze which is made up of ethylene and propylene glycol (13). Ethylene glycol is mixed with water so it is 50% of each liquid in the solution and has the highest boiling point than any other radiator fluid (5); its boiling point is 197.3°C and has a melting point of -12.9°C (12).
Liquids? 3. Aqueous solutions (when the covalent compounds are dissolved in water)? Covalent compounds cannot conduct electricity as liquid or aqueous solution because ions are needed to conduct electricity in water and there are no ions in a covalent compound. They cannot conduct electricity as a solid because the normal don’t transfer electrons unless they react with something else.
Introduction: Crystallization, purification, and isolation (may only be restricted to a solid) are insufficient ways to separate mixtures of compounds. Extraction is the recovery of a substance from a mixture by bringing it into contact with a solvent, which dissolves the desired material. Partitioning is the separation between two distinct phases (immiscible liquids) and also called fractional separation. Like recrystallization and distillation, extraction is a separation technique frequently employed in the laboratory to isolate one or more components from a mixture. Unlike recrystallization and distillation, it does not yield a pure product; thus, the former techniques may be required to purify a product isolated by extraction.
A) is neutralized by water B) is surrounded by water molecules C) reacts and forms a covalent bond to water D) aggregates with other molecules or ions to form a micelle in water Answer: B Page Ref: Section 3 11 9) Which would you expect to be most soluble in water? A) I B) II C) III D) IV Answer: A Page Ref: Section 3 10) Solutes diffuse more slowly in cytoplasm than in water because of A) the higher viscosity of water. B) the higher heat of vaporization of water. C) the presence of many crowded molecules in the cytoplasm. D) the absence of charged molecules inside cells.