if you are asked to "obtain about 3 g of sodium chloride weighed to the nearest 0.001 g should you weigh out exactly 3.000 g? explain your answer.

Answer 1

You may but that isn't required.
About 3 g means you could weigh
2.995, 2.900, 3.001, 3.050, 3.100, 3.200, etc. You want somewhere close to 3g and I would think anywhere between 2.500 and 3.500 would be ok. Others may think a better range is 2.750 to 3.250. It really depends upon the experiment being conducted. The spirit of the question means you want APPROXIMATELY 3 g but whatever amount you weigh you want it to be weighed to the nearest 0.001 g.

Answer 2

If you are asked to "obtain about 3 g of sodium chloride weighed to the nearest 0.001 g should you weigh out exactly 3.000 g? explain your answer.