CHEM 24112 Chapter Notes - Chapter 8: Lithium Chloride, Hydrogen Bromide, Carbon Suboxide

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

Calculate the molecular mass or formula mass (in amu) of each of the following substances:

(a) BrN₃

amu

(b) C₄H₁₀

amu

(c) NI₃

amu

(d) Al₂O₃

amu

(e) Fe(NO₃)₃

amu

(f) PCl₃

amu

(g) (NH₄)₂CO₃

amu

5. Decide whether the following elements a metal, nonmetal, or metalloid.

Se b. Cs c. Fe d. Cu e. Br f. Cl g. Si

6. Identify group and period for each of the following by referring to the periodic table. Also,

label each as metal, nonmetal or metalloid.

a. C b. Po c. Cr d. Mg e. B

7. Write the formula for the compound of each of the following pairs of ions.

a. Fe³⁺ and CN^- b. K⁺ and SO₄^2- c. Li⁺ and N^3- d. Ca²⁺ and P^3- e. Cr⁺³ and O^-2 f. Sr⁺² and O^-2

8. Name the following compounds:

Mg₃N₂ b. CrSO₄ c. CaO d. PbCrO₄

9. Write down the chemical formula of the following compounds:

Iron (II) phosphate b. Titanium (IV) oxide c. Thallium (III) nitrate

10. Name the following compounds:

SF₄ b. Cl₂O₇ c. N₂O₄ d. P₄O₆ e. PCl₃

PCl₅ g. Cl₂O₆