Chemistry 5070 · O Level · Identification of ions and gases

Identification of ions and gases — practice question

The presence of water may be tested using either anhydrous cobalt(II) chloride or anhydrous copper(II) sulfate. Which observation would be correct when water is present?

  • AAnhydrous cobalt(II) chloride turns from blue to white.
  • BAnhydrous cobalt(II) chloride turns from pink to blue.
  • CAnhydrous copper(II) sulfate turns from blue to pink.
  • DAnhydrous copper(II) sulfate turns from white to blue.

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