Tungsten has the highest melting point of any metal in the periodic table: 3422°C. The distance between W atoms in tungsten metal is 2.74 Å.

(a) What is the atomic radius of a tungsten atom in this environment? (This radius is called the metallic radius.)

(b) If you put tungsten metal under high pressure, predict what would happen to the distance between W atoms.

 

what is the atomic radius of tungsten in nm?

Tungsten crystallizes in the unit cell shown here.

(a) What type of unit cell is this? 

(b) How many tungsten atoms occur per unit cell?

(c) If the edge of the unit cell is 316.5 pm, what is the radius of a tungsten atom? (Hint: The W atoms touch each other along the diagonal line from one corner of the unit cell to the opposite corner of the unit cell.)

The tungsten metal used for filaments in light bulbs is made by reaction of tungsten(VI) oxide with hydrogen:
WO3(s)+3H2(g)→W(s)+3H2O(g)
The above reaction was performed and produced 5.78 g of tungsten.

(c) How many moles of hydrogen were required to produce the 5.78 g of tungsten?

(d) How many grams of tungsten(VI) oxide must you start with to prepare 5.78 g of tungsten? (For WO3, MW=231.8amu.)

(e) How many grams of hydrogen must you start with to prepare 5.78 g of tungsten?