1. When copper carbonate reacts with excess acid, carbon dioxide is produced. The curves shown were obtained under different conditions. The change from P to Q could be brought about by A. increasing the concentration of the acid B. increasing the mass of copper carbonate C. Adding a catalyst D. Decreasing the particle size of the copper carbonate 2. When 3.6g of butanal (relative formula mass = 72) was burned, 134kJ of energy was released.
Calculate the percent error in the molar mass value. Enter both values in the Data Table. Molar Mass Na2CO3 = 105.99 g/mol – this is the closest molar mass to what I calculated, so the unknown M2CO3 must be sodium carbonate. Percent Error: 93.08g/mol – 105.99 g/mol (100) = 12.18% error 105.99 g/mol DISCUSSION Review the procedure and list the possible sources of error that would cause either the molar mass of the unknown to be (a) too high or (b) too low. The goal of this lab was to discover the unknown group 1 metal (M) of the compound M2CO3 by dissolving the compound in water and adding a solution of calcium chloride, CaCl2 to the solution in order to precipitate the carbonate ions to reveal the molar mass of the unknown element, thus determining the identity of the unknown element.
Find the volume of 2.40 mol of gas whose temperature is 50.0 °C and whose pressure is 202 kPa. 6. How many moles of gas are contained in a 50.0 L cylinder at a pressure of 10100 kPa and a temperature of 35.0 °C? 7. Determine the number of grams of carbon dioxide in a 450.6 mL tank at 1.80 atm and minus 50.5 °C.
Calculate the surface area of the circle formed (πd2/4): Surface area = .785 cm2 2. Calculate the number of molecules on the top layer. We must convert the surface area in centimeters squared to nanometers squared and then multiple that by the surface area of a sodium stearate molecule. Convert the surface area of the circle formed (#1) to molecules per layer using the matrix below: Answer = 4.76*10^14 molecules/top layer 3. Calculate the concentration of grams of sodium stearate per milliliter of diluted solution.
Archimedes’ method Object Mass (g) Mass of Displaced Water (g) Volume of Displaced Water (mL) Density (g/mL) Metal Bolt 42.5 25 25 25 Magnet 16.2 3.5 3.5 3.5 Questions: An unknown, rectangular substance measures 3.6 cm high, 4.21 cm long, and 1.17 cm wide. If the mass is 21.3 g, what is this substance’s density (in grams per milliliter)? 1.2 g/ml A sample of gold (Au) has a mass of 26.15 g. Given that the theoretical density is 19.30 g/mL, what is the volume of the gold sample? 1.35 mL What would happen if you dropped the object into the beaker while using the Archimedes’ Principle method instead of submerging the object? The measurements would be the same.
According to Bender oxygen and hydrogen are elements other than carbon used to define mole. A mole is the quantity of an element that weighs out in grams the amount of an element specified by the atomic weight. Work Cited Bodner , George M. "How was Avogadro's number determined?." scientific american. © 2013 Scientific American, a Division of Nature America, Inc., 16 Feb 2004.
Number of moles of CuCl2 used = [pic] =[pic] = 0.127 moles Therefore, Molarity of CuCl2 = [pic] = [pic] = 0.063 mol/dm3 Number of moles of ethylenediamine used = [pic] =[pic] = [pic] = 0.1 mole Therefore, Molarity of ethylenediamine = [pic] = [pic] = 0.05 mol/dm3 2. Plot a graph of absorbance versus mole fraction of ligand. 3. From the graph, look for the maxima and from the corresponding mole fraction, determine the formula of the complex. Maximum absorbance occur when mole fraction of ligand is 0.65.
0.15 M NaCl solution = 0.15 moles of Na+ atoms + 0.15 moles of Cl- atoms = 0.30 Osmoles In other words, the solution is said to have an osmolarity of 0.30 Osm (or 300 mOsm) Assume the osmolarity of the ICF of body cells to be 0.300 Osm (300 mOsm) 2nd, determine if the solute is a PENETRATING particle or is NON-PENETRATING. 3rd, determine whether a concentration gradient of NON-PENETRATING particles exist or not. If a gradient exists, determine where the higher concentration of non-penetrating particles exist; in the ICF or the ECF? (Assume the 300 mOsm concentration of particles in the ICF of body cells is composed of non-penetrating particles) 4th, repeat your definition of osmosis in order to determine if water will move: a. into the cell b. out of the cell c. not move into or out of the cell Osmosis is the diffusion of water across a membrane from a region of lower concentration of non-penetrating particles into a region of higher concentration of non-penetrating