CHEM:1110- Principles of Chemistry I Spring 2016

CHEM:1110- Principles of Chemistry I Spring 2016IV Pre-Laboratory Activity (Topic 2).Reminder: You will turn in a copy of your pre-lab as soon as you walk into the laboratory.1. Look up the Material Safety Data Sheet (MSDS) for the chemicals that you will usein experiment 2. ( Read the pertinent information about allof the chemicals that are used in this experiment. List all chemicals (and only thosechemicals) that have a health hazard rating of three or greater.For problems 2 & 3 the density of the sample is 0.9977 g/mL and the molar mass ofcalcium carbonate is 100.0 g/mol.2. Calculate the mass of calcium carbonate present in a 50.00 mL sample of an aqueouscalcium carbonate standard assuming the standard is known to have a hardness of75.0 ppm (hardness due to CaCO3).3. If the 50.00 mL sample from problem 2 above was titrated with a 0.00501 M EDTA what volume of EDTA solution would be needed to reach the endpoint? (Youranswer should be given in milliliters. Reminder: this volume what you should expectfor your first sample that you will use to calibrate your expectations.)4. A group of students titrate a calcium carbonate standard solution repeatedly in sixexperimental trials. Based on the six trials the group determines that the averageconcentration of the standard is 75.3 ppm with a standard deviation of 0.6 ppm.Using the equation for the Student’s t confidence interval found on page 43 of yourlab manual and a t-value of 2.57 for a 95% confidence interval calculate theconfidence interval for which there is a 95% chance of finding the “true value” ofthe standard solution’s concentration based on the data. Put your answer in theformat # lower limit < “true value” < # upper limit. (Page 43 has an example thatmay be helpful.)5. What harmful substance was recently found in the water supply (and in residents’blood) in Flint Michigan? Hint: search Flint Water Crisis or see articles such as: units and significant figures count on quantitative problems.33B