Chem2 help

Name __________________________

Module 2

Post-Lab Assignment

Short Answer (45 points)

Answer the following questions based on material covered in this module. (5 points each)

(You must use complete sentences when answering each question.

1-point deduction per question not answered in complete sentences.)

1) How many significant figures are in your cm measurement of Rod A? How did you figure out how many decimal places to use in your answer?

2) Could you use a 100-mL volumetric flask to measure 50.0 mL of a liquid? Explain.

3) Which types of measuring devices could you use to measure 50.0 mL of a liquid? Explain.

4) Chefs often estimate the amount of ingredients needed for a dish. Do you think it would be a good idea to estimate rather than weigh the amount of chemicals needed for an experiment? Explain.

5) When the meniscus is above eye-level, what is the sign of your error? (positive or negative)

6) When the meniscus is below eye-level, what is the sign of your error? (positive or negative)

7) What is the effect on the volume when reading the meniscus above eye-level? below eye-level?

8) Examine the data you have collected in this section. Of the three different types of apparatus used in Part III, which do you think would give you:

(a) the most precise measurement of volume?

(b) the least precise measurement?

9) Based on your results in Part IV of the experiment, what does the percent error in the masses of your samples tell you about the accuracy of estimating? Is it a good idea or bad idea? Explain.