Exercise 2.58. Part A:Determine the number of Kr atoms ina 5.55 −mg sample of krypton.
Part B:Determine the molar mass, M, of anelement if the mass of a 2.80×1022−atom sample of the element is2.09 g.
Part C: Determine the identity ofan element if the mass of a2.80×1022−atom sample of the element is 2.09 g.(Answer choices: titanium.potassium, scandium, calcium.)
Exercise 2.56. Withoutdoing detailed calculations, indicate which of the followingquantities contains the greatest number of atoms: 6.022×1023Niatoms, 25.0 g nitrogen, 52.0 g Cr, 10.0cm3 Fe(d=7.86g/cm3). (answer choices: Ni, Nitrogen, Cr, Fe)
Excercise 2.62. A particular lead–cadmium alloy is 8.0% cadmiumby mass. What mass of this alloy, ingrams, must you weigh out to obtain a sample containing6.30×1023 Cdatoms? Express your answer using two significantfigures.
Exercise 3.6 Determine the mass,in grams, of,
Part A 7.32 molN2O4
Part B 3.22×1024 O2 molecules
Part C 18.8 molCuSO4â‹…5H2O
Part D 4.14×1024 molecules of C2H4(OH)2
Excercise 3.11
Part A molesof N2O4 in a 145 −gsample
Part B N atomsin 43.5 g of Mg(NO3)2
Part C N atomsin a sample of C7H5(NO2)3 that has the same number of O atoms as12.4 g C6H12O6
thank you in advance^^
