Which of the following is an example that includes evidence of a chemical reaction? a. A sample of zinc is placed in water and it settles to the bottom
b. A solid block of ice is heated and it completely melts into a liquid.
c. Sugar that is burned gives off an odor and turns brown and then black.
d. A tomato is chopped up into smaller pieces.

Benzonitrile (c6h5cn) is reduced to two different products depending on the reducing agent used. treatment with lithium aluminum hydride followed by water forms k, which has a molecular ion in its mass spectrum at 107 and the following ir absorptions: 3373, 3290, 3062, 2920, and 1600 cm-1. treatment with a milder reducing agent forms l, which has a molecular ion in its mass spectrum at 106 and the following ir absorptions: 3086, 2850, 2820, 2736, 1703, and 1600 cm-1. l shows fragments in its mass spectrum at m/z = 105 and 77. propose structures for k and l and choose an explanation for how this could be concluded.