Carbon dioxide and water react to form methane and oxygen, like this: CO₂(g) + 2H₂O(g) → CH₂(g) +20₂(g) The reaction is endothermic. Suppose a mixture of CO₂, H₂O, CH₂ and O₂ has come to equilibrium in a closed reaction vessel. Predict what change, if any, the perturbations in the table below will cause in the composition of the mixture in the vessel. Also decide whether the equilibrium shifts to the right or left. perturbation The temperature is lowered. change in composition The pressure of CO₂ will ? The temperature is raised. The pressure of CH4 will ? v shift in equilibrium to the right O to the left O (none) O to the right O to the left O (none)

H8.

For the reaction 2A(g) s B(g) K. = 69 For the reaction A(g) = ½ B(g) Kc = For the reaction ½ B(g) A(g) Kc = Report each answer to two significant figures. Do NOT use scientific notation.

Many common materials that we ingest, though quite safe in reasonable quantities, become toxic when taken in very large doses. A measure of toxicity is the LD50 value (Lethal Dose, 50%). It is the quantity of material, expressed in mg of material per kg of subject-body-weight that, if administered to a population of subjects, would cause 50% of the population to die. The LD50 value for FD&C Red Dye No. 40 is >10,000 mg/kg in rats. Assume that the LD50 value for humans is the same as for rats. Calculate the number of mg of Allura Red present in an 8 fluid ounce glass of the beverage you used in this lab. Assume that the concentration of Allura Red in the beverage is 0.000054 M. The molar mass of Allura Red is 496.42 grams/mol 1 fl oz = 29.5735 mL Do not include units with your answer.

A student synthesizes tin oxide to create a compound with generic formula SnxOy. She does this by combining 30.80 g of tin and when the tin oxide product is produced, the total mass of the product is 39.10 g. Consider the starting mass of the tin (Sn) and the ending mass of the SnxOy product. To find the mass of oxygen in the product, you would _____ A) add the mass of tin from the mass of the product. B) subtract the mass of tin from the mass of the product. C) multiply the mass of tin from the mass of the product. D) divide the mass of tin from the mass of the product.

The world population is estimated to be 7.4 x 109. Nauru is the smallest island nation and comprises 1.5 x 10-4% of the world population. If the percentage of left-handed people is approximately 12%, estimate the number of left-handers on the island of Nauru.

The number of oxygen atoms in 20.18 grams of Al(NO;); is: O 1.712 x 1023 O 0.09474 5.135 x 1023 O 5.705 x 1022

A 15000 L tailings pond at a mine site was analyzed for cadmium contamination. First, a 25.0 mL sample of water was removed from the pond. Then the solution was evaporated to dryness, and 56.1 mg of cadmium was recovered (the identity of the metal was confirmed through other methods). Assuming the water is homogeneously distributed throughout the pond, what is the concentration of cadmium in the tailings pond?