Which of these is an indication that a chemical reaction has occurred?

A. melting of a substance

B. boiling of a substance

C. formation of a precipitate

D. freezing of a substance

16. A sample of nitrogen gas, N2, is collected in a 100 ml container at a pressure of 688 mm Hg and a temperature of 565 °C. How many grams of nitrogen gas are present in this sample?

Salt crystals look like tiny cubes. Salt is part of the ___ crystal system. a. hexagonal b. isometric c. monoclinic d. triclinic

1. Adam found a block made of lead. The density of lead is 11.36 g/cm3. The lengths of the block's sides are 3.5 cm, 3.6 cm, and 2.6 cm, respectively. How heavy is Adam's block?

One mole of an ideal gas, for which CV, m = 3/2R, initially at 298 K and 1.00 * 105 Pa undergoes a reversible adiabatic compression. At the end of the process, the pressure is 1.00 * 106 Pa. Calculate the final temperature of the gas.

2 kg nitrogen reacts with 1 kg hydrogen. calculate the mass of ammonia

The molar mass of water (H2O) is 18.02 g/mol. Yun needs 0.025 mol H2O for a laboratory experiment. She calculates that she needs 72.0 g H2O for the experiment. Yun's calculation was incorrect because she set up her unit conversion incorrectly.

I'm doing isotope homework and I need the find the number of protons, neutrons, and electrons first one is chromium-58 and chromium-63

Trisha and her lab partner were conducting a variety of experiments to produce gases: hydrogen, oxygen, and carbon dioxide. In one experiment, they added a piece of magnesium ribbon to 10 milliliters of hydrochloric acid.

what mass of magnesium is required to react with excess nitrogen to produce 0.500 mol magnesium nitrade

Silver chromate is sparingly soluble in aqueous solutions. the ksp of ag2cro4 is 1.12 * 10-12 m3. what is the solubility (in mol/l) of silver chromate