Question

13. Calculate the density of sulfur if you have 9.92x102 atoms in 2.51 x10 L? UNITS!!! 14. Calculate the number of hydrogen atoms in 0.252 ML of sulfuric acid. (D-1.02g/mL) 15. Indicate whether the following is true or false. If it is false, correct it to make it true. a. If you have 1 g samples of different elements, the sample with the smallest molar mass contains the fewest atoms. b. On average, one lithium atom weighs 6.941 amu. Every H atoms weighs 1.008 amu. d. A certain mass of solid Na contains fewer atoms than the same mass of gaseous Ne. e. One mole of NH3 weighs more than one mole of H2O. f. C. The number of Cu atoms in 100 grams of Cu (s) is the same as the number of Cu atoms in 100 grams of copper (lI) oxide. There are more hydrogen atoms in 2 moles of NHa than in 2 moles of CHa. g.

Answer 1

Ans 13 :

Number of mol of sulfur atoms = total atoms / (6.022 x 10²³ atoms/mol)

= (9.92 x 10²³ atoms) / (6.022 x 10²³ atoms/mol)

= 1.65 mol

mass of one mol of sulfur atoms = 32.065 g

so mass of 1.65 mol = 1.65 x 32.065 g = 52.82 g

density = mass / volume

here mass = 52.82 g

volume = 2.51 x 10⁴ uL = 25.1 mL

putting values :

density = 52.82 g / 25.1 mL

= 2.10 g/mL