Lab Techniques & Measurements Pre Lab Questions: (4pts)
1. What will you learn after completing the lab?
-The experiment will introduce different level of precision and measuring to the appropriate decimal place and will be familiar with measurements and weight.
2. Write the symbols and equation used to make a dilute solution from concentrated or stock solution. - The concentration of substance is described as molarity and this can be expressed as – Molarity = moles of substance per liter of solution.
3. Write the mathematical relation to calculate % error of your experimental results?
-Percentage error % = measured value –accepted value x 100
4. Write the relation between Kelvin and Celsius scale, and Fahrenheit and Celsius scale. -The Kelvin and Celsius scale are the same both are one hundred of between freezing point of water and boiling point at standard atmospheric pressure.
-Fahrenheit and Celsius scale it is an interval of 180 to cover the same range as 100 Celsius. The degree Fahrenheit is only 100/180 as large as degree Celsius.
5. What is a meniscus? Which level of meniscus would you record to get the correct volume of water from measuring devices?
-Meniscus is a measurement used for measuring liquids, for water and most liquids the line with the center of the meniscus reading in the bottom is used.
6. How would you clean the lab after completion?
- Items in labpaq are generally used multiple times. Always clean and return un used items to the bag after completing experiment.
-Clean used and left over chemicals with paper and place in a garbage or flush down using enough amount of water.
-To clean from graduate cylinder pour the solution and clean with water several times.
-Use a liquid dish washing detergent with worm water.
-use soft cloth or to clean residue from the surface.
-Dry test graduate cylinder by placing them upside down in the test tube or using paper towel.
Title: 1pt __Lab technique and measurement
Read the entire procedures and write in your own words.
-Measure the length of computer, spoon and pen in cm and mm.
-Measuring the temperature of water from the tap, first hot water and the boiling water and measuring the water after you boil the water for 5 minute.
-Measuring cold water from the tap and measure the ice pack.
- In calculating the volume and mass calculate the volume of magnet and record in data.
-For displacement method place the magnet in scale and record the mass.
-Place the magnet in graduate cylinder and record. Carefully pour the water from cylinder collect the metal and drain.
Results: (2pts each for 1-4 & 3pts for 6)
1. Length Measurement: ( estimate the second decimal place and first decimal place for measurement in cm and mm, respectively) |Length |cm |mm | |Computer | 41.5 | 415 | |Spoon | 6.5 | 65 | |Pen | 13.5 | 135 |
2. Warm Temperature Measurement (in Celsius scale): (estimate the second decimal place) |Temperature of hot water from your tap | 42 oc | |Temperature of boiling water | 98 oc | |Temperature of water after continuous | 100 oc | |boiling for five minutes |...