The density of lead is 11.4 g/cm3. Calculate the mass of a lead ball (in grams) with a radius of 0.50 mm.

To prepare a solution of KCl, you weigh out 1.5672 (± 0.0003) g and dissolve it in a volumetric flask of 250.00 (±0.50) mL in volume. Express the molarity of the solution and its uncertainty with appropriate number of significant figures. (Formula mass of KCl is 74.551 ± 0.004 g/mol)

Using the mass of the protonfrom Table 2.1 and assuming its diameter is 1.0 * 10-15 m,calculate the density of a proton in g>cm3.

8. The distance between the centers of the two oxygen atoms in an oxygen molecule is 1.21 × 10-8 cm. What is this distance in inches?

The density of Neon (Ne) at a specific temperature and pressure is 3.21 x 10-5 lb/in3. Calculate the volume of 1.2 x 108 Ne atoms, in cm3, under these conditions. 1000 lb = 453.6 g 1 inch = 2.54 cm

A sodium chloride solution was prepared by dissolving 0.0998 \pm 0.0005 g NaCI (58.443 \pm 0.001 g/mol) in 100.00 \pm 0.08 mL of water. Calculate the concentration of NaCl in the solution and its absolute uncertainty. Report the concentrationwith the appropriate number of significant figures.

If a sample of gold alloy has a mass of 87.7 g and is 78.3% gold by mass, what percentage of the alloy is made up of other metals? Write your answer to the nearest tenth of a percent. (I had to alter the wording of this question since it wasn't calculating significant figures properly, so if you got it wrong because of significant figures you can assume you probably actually got it correct.)

3

How many molecules are contained in 5.00 microliters of methanol (CH4O)? The density of methanol is 0.792 g/mL. Use these atomic masses: C = 12.011 amu; H = 1.008 amu; O = 15.999 amu. Input your result in scientific notation using the format with the lower case e representing the x10. For example, in this format the number 1.234x109 would be expressed as 1.234e9. The number 1.234x10-9 would be expressed as 1.234e-9  Not these answers  0.1569 1.23 0.1569 0.0001

To aid in the prevention of tooth decay, it is recommended that drinking water contain 0.700 ppm fluoride, F−. How many grams of F− must be added to a cylindrical water reservoir having a diameter of 5.62×102 m and a depth of 13.02 m? How many grams of sodium fluoride, NaF, contain this amount of fluoride?