Report for Density Determination

Report of Density Determinations Density is defined as the mass of substance per unit volume. Both pure substances and solutions are applicable. Today we are going to determine the Density of rock chunks and NaCl solution. In this experiment, we will determine the mass and volume of each object and then we will calculate the ratio—the density. In the first part of the experiment, we should measure the density of some irregularly shaped chunks of rock. The Weight of rocks is 18.769g. To calculate the volume of rocks, We make use of Archimedes Principle: that is, an insoluble solid will DISPLACE a volume of water equal to its own volume. The volume before adding rocks and after adding rocks are 50 ml and 58 ml. Hence the volume of rocks is 58 cm3 minus 50 cm3 which is 8 cm3. The density is 18.769g divided by 8 cm3 which is 2.34g/ cm3. The chunks of rock should be returned to the waste beakers after use and we should not pour them into the sinks.

In the second part of the experiment, the chemical involved is sodium chloride which has no major health risks we should measure the density of the density of NaCl Solution. The concentration of NaCl which is assigned is 15%. We need 15g NaCl and 85 ml distilled water to make 15% NaCl solution. Firstly, we should make the NaCl solution. We first measure the weight of beaker which is 67.039g and then we add NaCl on the a weighing paper on the beaker and the total weight is 81.158g. Then we thoroughly dissolve the NaCl in the water by stirring for several minutes and the solution must be homogeneous before determining its density. After that we measure the weight of beaker plus NaCl plus water which is 164.696g. Therefore the mass of NaCl is 81.158g minus 67.039g which is 14.119g and the volume of that is 85ml. Hence the actual concentration is 14.119g devided by 85 ml times 100% which is 15.36% which is approximate to the assigned proportion. To calculate the density of the