CHM 113 Exam Questions And Answers (Verified And Updated)

CHM 113 Exam Questions And Answers (Verified And Updated) Density - answermass divided by volume Specific Gravity - answerThe ratio of the density of a substance to the density of water Intensive property - answerProperties independent of mass. Examples: density, specific heat, equivalent weight Extensive property - answerProperties dependent of mass. Example: volume and mass Volume of a cylinder - answerV = pi(r)^2h Mass of water displaced by a rock with 143g in air and 82 g in water - answerMass of water displaced = Mass of rock in air - mass of rock in water Volume of water displaced by a rock - answerV = mass of water displaced divided by density of water Density of rock with 143g in air, 82 g in water - answer= mass of rock in air divided by the volume it displaces in water If a piece of PVC is suspended in solution than the density of the PVC is - answerequal to the density of the solution Which has a greater density: water or ice? - answerWater (Ice floats on water) What are the units of density? - answerg/mL and g/cm^3 Why is density important? - answerIt identifies a substance What is the conversion factor of cm^3 and mL - answer1 cm^3 = 1 mL What is the normal order of density for the states of matter? - answerGas is the least dense, liquid is more dense and solid is the most dense. What property of adipic acid is used in the separation during the adipic acid lab? - answersolubility What is the formula for Adipic Acid? - answerH2C6H8O4 What is the unit of specific heat? - answerthere is no unit What does density tell us? - answerDensity relates information on how the atoms or molecules that make it up are arranged in space. Substance with larger density is more tightly packed than the substance with smaller one. What is the structure of adipic acid? - answerHOOCCH2CH2CH2CH2COOH What is adipic acid used for? - answerProduction of nylon; additive to drinks Solubility of Adipic Acid - answerAdipic acid's solubility is temperature dependent. It is more soluble in hot water and slightly soluble in cold water. This property is the principle of recrystallization of adipic acid. What impurities make the crude adipic acid brown? - answerOxidized compounds and fine carbon particles. What substance absorbs the impurities? - answerCharcoal. One scoop is added to the beaker. Why is fluted filter paper used instead of flat filter paper? - answerIt has a larger surface area for contact with the solution, thus leading to a more rapid rate of filtration. Why was the adipic acid heated? - answerTo dissolve is completely in hot water. Why was the adipic acid cooled? - answerSo the acid will crystallize How do you calculate percent yield of adipic acid? - answerWeight of pure adipic acid/Weight of crude adipic acid x 100 What is the difference in melting point between Crude and Pure adipic acid? - answerPure adipic acid will melt at a temperature close to the literature value. It will have a narrow melting point range. The purer the compound is, the smaller is melting point depression (Literature value - experimental value) and the smaller is melting point range. The crude will have a large melting point range and the melting point will be less than the pure on. The impurity interrupts the normal intermolecular force. How much pure adipic acid was recovered if there was a crude sample of adipic acid that weighed 20.421 g and a yield of pure adipic acid of 73.5%? - answerPure/Crude x 100 = 73.5% 20.421g(0.735) = 15.009 g If the adipic acid was 15 degrees below the literature value, was his adipic acid pure or impure? - answerImpure What could cause the adipic acid to still be impure? - answerThe impurities were not all filter out.