List of top Chemistry Questions on Redox reactions asked in GUJCET

The half-life of a radioactive substance is 5730 years. If carbon-14 decays and only 80% of it remains after a certain period, what is the time elapsed (in years)?

For the given reaction, what is the correct rate law?
\[ \frac{d[A]}{dt} = -6 \frac{d[B]}{dt} = -4 \frac{d[C]}{dt} = 3 \frac{d[D]}{dt} = 4 \frac{d}{dt} \]

What is the oxidation state of Mn in the given reaction involving MnF\(_3\) and Mn\(_2\)O\(_3\)?