Inorganic Chemistry Answers

Lead metal is obtained from lead sulfide through the following reaction:

2PbS(s) + 2C(s) + 3O₂(g) → 2Pb(s) +2CO(g) + 2SO₂(g)

(a)If 100g of PbS is reacted with excess C and O_2, calculate the mass of lead metal obtained. ( 5 )

(b)Suppose 100 g of PbS is reacted with 4g of C and 20g O₂.

Find the limiting reactant for this reaction.

( 4 )

(c)For question (b) above, calculate the mass of lead metal obtained. ( 4 )

(d)By referring to the question (c) above, If 31.2g Pb is obtained as the yield. Calculate the percentage of yield. ( 2 )

(e)Calculate mass of oxygen is needed to produce 500g of lead metal.

Suppose 100 g of PbS is reacted with 4g of C and 20g O₂.

Find the limiting reactant for this reaction.   

The chlorine-containing narcotic drug pentaerythritol chloral has 21.51% C, 2.22% H, and 17.64% O, by mass, as its other elements. Its molecular mass is 726 u. What are the empirical and molecular formulas of pentaerythritol chloral?

The volatile liquid ethyl mercaptan, C₂H₆S, is one of the most odoriferous substances known. It is sometimes added to natural gas to make gas leaks detectable. How many C₂H₆S molecules are contained in a 1.0 mL sample? The density of liquid ethyl mercaptan is 0.84 g/mL.

1.      What is the oxidation state of the underlined element in (a) P₄, (b) Al₂O₃, (c) MnO₄ ^-, (d) NaH, (e) H₂O₂; (f) Fe₃O₄?

(a)

Choose and explain which element has the greater value for the following properties:

i. electron affinity.

    Na or F. 

ii. electronegativity.

        Cl or Ca.        

iii. ionization energy.

       S or Se.

iv. atomic radius.

    C or Sn.

v. metallic property.

      Si or Br.

(b)

Write the electron configurations for the following atoms/ions:

     i.       Ca.

    ii.       S.

  iii.       Mg²⁺.

  iv.       O^2-.

    v.       Fe³⁺.

2.

Lead metal is obtained from lead sulphide through the following reaction:

          2PbS(s) + 2C(s) + 3O₂(g) → 2Pb(s) +2CO(g) + 2SO₂(g)

(a)

If 100g of PbS is reacted with excess C and O_2, calculate the mass of lead metal obtained.

(b)

Suppose 100 g of PbS is reacted with 4g of C and 20g O₂.

Find the limiting reactant for this reaction.     

(c)

For question (b) above, calculate the mass of lead metal obtained.

(d)

If 31.2g Pb is obtained as the yield. calculate the percentage of yield.

(e)

Calculate mass of oxygen is needed to produce 500g of lead metal.

By referring to the chemical equation given, calculate the volume of nitrogen gas in litres, required to react with 40.0 g of magnesium at a pressure of 2.25 atm and a temperature of 15 °C.

            3Mg (s) + N₂ → Mg₃N₂ (s)

A nitrogen gas container has a volume of 35.0 L. Calculate the mass of nitrogen in the container if the gas has a pressure of 1800 torr at 42°C.

A gas is initially at volume 40.0 L, pressure 600 mmHg and temperature 35 °C. Calculate the final pressure of the gas in atm if the volume and temperature are changed to 2500 mL and 225 K, respectively.