A sample of air has a volume of 140.0 mL at 67°C. At what temperature would its volume be 50.0 mL at
constant pressure?

  about 121.5 K or -151.7 °C

Explanation:

Volume of an ideal gas is proportional to the absolute temperature. At 67 °C, the absolute temperature is 67+273.15 K, or 340.15 K.

Then 50.0/140.0 times that temperature is ...

  (5/14)(340.15 K) ≈ 121.482 K ≈ -151.668 °C

The volume would be 50.0 mL at a temperature of about 121.5 K or -151.7 °C.

- aluminum and copper chloride.

- the chloride ion to separate the aluminum from the oxygen so that the aluminum can react with the copper ions (and the water molecules).

answerlinnaeus;