Question

23.40245 What's the proper way to report (write) the reading shown in the analytical balance shown in the figure A) 23.402 B) 23.40245 C) 23.4025 D) 23.4 E) Any of the answers A-D are valid answers. How would you notate (write) the amount of fluid delivered from the "fill line" of the volumetric pipette shown in the figure, if the following markings are on the pipette: 25 mL +/- .02 mL TD at 25 C A) 25.00 mL B) 25.0 mL C) 25.000 mL D) 25 mL E) All answers, A-D, are valid 21 Burettes are designed to deliver fluid. Thus, you record how much fluid has been delivered opposed to how much remains in the burette. How would you report (write) the volume delivered from the burette shown in the figure, while communicating proper uncertainty. as If a burette measures 1.01 mL prior to delivering fluid and 35.23 mL after delivering fluid, how much fluid is delivered from the burette (be sure to maintain proper uncertainty in your final answer). A) 34 mL B) 34.2 mL C) 34.22 mL D) all answers, A-C, are valid Question 6 (1 point) In Part A, students will measure and calculate a quantity using both precise and imprecise lab equipment to show how equipment with high precision leads to high precision results. What is the quantity that will be measured and compared with the two sets of lab equipment? A) Volume B) Mass C) Length D) Density Question 7 (1 point) For Part B, the lab team will do a series of dilutions from the concentrated "stock solution" Should Tommy Takeover do all of the dilutions to insure more accuracy? A) No, it will save time to have all of the group divide up the dilution work. B) No, It's important that every group member gets to practice the pipetting skill. C) Yes, Since Tommy Takeover also has the best "lab hands" the final dilution will be most accurate if Tommy runs the show. D) Yes, Even though everyone pays for the class and wants to learn lab skills from hands on pipetting to graphing on excel, Tommy has done a little work in industry so he has experience and thus, there's less of a chance to break some equipment. Question 8 (1 point) Read Preparing glassware to avoid contamination on page 8 and 9. Since "the 4th rinse is strategic", what should you rinse a burette with prior to filling and using it to add 15.00 mL of sodium chloride solution to a reaction? A) The same sodium chloride solution you are about to dispense. B) Tap water C) Pure (deionized) water D) Either A or C will work If a 200.00 mL volumetric flask is used to preparea 5.0 mM copper II sulfate solution, should the solution be stored in the volumetric flask? A) Yes, volumetric glassware can be used to measure and store reagents. B) Yes, provided the volumetric glassware has a cap or parafilm can be used for a cap. C) No, Not only should chemicals not be stored in volumetric glassware, all volumetric glassware should be promptly cleaned after use to prevent future contamination. D) No, because CCD will run out of volumetric glassware. It can be used for storage long as its not needed for other labs. as

Answer 1

Ans 1

Analytical balances are used for very accurate readings to the nearest 0.001 g.

Proper way to reading upto three decimals.

23.402 g

Option A is the correct answer

Ans 2

Volumetric pipettes are used for very accurate readings to the nearest 0.02 mL

Proper way to reading upto two decimals.

25.00 mL

Option A is the correct answer

Ans 3

Burettes are used for very accurate readings to the nearest 0.01 mL and measured at the bottom of the miniscule.

The reading shown in the figure upto two decimals.

20.00 mL

Uncertainty = +/- 0.01 mL

Proper volume delivered = 20.00 +/- 0.01 mL

Ans 4

Volume prior to delivering fluid V1 = 1.01 mL

Volume after delivering fluid V2 = 35.23 mL

Volume delivered = V2 - V1 = 35.23 - 1.01 = 34.22 mL

Since Burettes are used for very accurate readings to the nearest 0.01 mL

Option C is the correct answer