Question

1) A 1.4326 g of sample of a new compound has been analyzed and found tocontain the following masses of elements, carbon,0.7263 g; hydrogen, 0.08127 g; nitrogen, 0.1412 g; oxygen, 0.4838 g. Calculate the empirical formula of thecompound.

2) Using average atomic masses, calculate the number of atomspresent in each of the following samples.

(a) 2.68 g of gold

(b) 0.000265 mol of platinum
(c) 0.000265 g of platinum
(d) 5.8 lb of magnesium
(e) 1.50 mL of liquid mercury (density = 13.6 g/mL)
(f) 4.45 mol of tungsten
(g) 4.45 g of tungsten

3) Calculate the number of moles of the indicated substance present ineach of the following samples.

(a) 20.4 mg of nitrogen dioxide

(b) 1.76 g of copper(II) nitrate

(c) 2.47 g of carbon disulfide
(d) 4.92 g of aluminum sulfate
(e) 2.82 g of lead(II) chloride
(f) 61.3 g of calcium carbonate