Plastics becoming brittle after being left in the sun ... Is it exothermic or endothermic?

Be sure to answer all parts. For the equilibrium 2 H2S (g) ⇌ 2 H2 (g) + S2 (g) Kc = 9.0 * 10-8 at 700°C the initial concentrations of the three gases are 0.740 M H2S, 0.740 M H2, and 0.370 M S2. Determine the equilibrium concentrations of the gases.

Write and balance the chemical equations for the synthesis of the triiodide and pentaiodide compounds.

Calculate the mass percentage of nacl in a solution containing 1.50 g of nacl in 50.0 g of water.

What temperature does water boil at using the degrees Celsius

What do scientists call organisms, such as plants, which make their own food?

Which of the follwing is a pure substance: sugar, salt, water, or pepper? Explain how you know.

A chemistry student needs of isopropenylbenzene for an experiment. She has available of a w/w solution of isopropenylbenzene in carbon tetrachloride. Calculate the mass of solution the student should use.

Can an organism carry out cellular respiration without photosynthesis?

Predict the product for PtCl4 + F2

Calculate the formula mass of ethanol, c2h5oh. express your answer to three significant figures and include the appropriate units.