A white precipitate forms if sulfate ions are present. Explain why, in a test for sulfate ions, the sample is acidified with hydrochloric acid first. Carbonate ions also produce a white ...

Unlike the other tests described on this page, the test for carbonate ions works whatever acid is added. Explain why, in a test for sulfate ions, the sample is acidified with hydrochloric acid first.

In an ion propulsion system, electrons are fired into a magnetic field containing the noble gas xenon. When a xenon atom is hit, it loses one of its negatively charged electrons and turns into a ...