At high temperatures phosphine PH3 dissociates into phosphorus and hydrogen by the following reaction 4PH₃一P₄ + 6H₂ At 800° C the rate at which phosphine dissociates is "严=—3.715 ₓ 10~⁶C，ph₃ dt for t in seconds. The reaction occurs in a constant volume, 2-liter vessel, and the initial concentration of phosphine is 5 kmol/m³ a. If 3 mols of the phosphine reacts, how much phosphorus and hydrogen are produced? b. Develop expressions for the number of moles of phosphine, phosphorus and hydrogen present and any time, and determine how long it would take for 3 mols of phosphine to have reacted.

1.5.41 EQuestion Help The granular fertilizer 13-13-13 s composed of 13% nitrogen, 13% phosphate, and 13% potassium. Similarly the fertilizer 20-17- ls composed of 20% nitrogen 17% phosphate, and 0% potassium. If a gardener mixes a 15 pound bag of 13-13-13 with a 10 pound bag of 20-17-0, what are the concentrations of nitrogen, phosphate, and potassium in the mixture? Express the answers as percents. The concentration of nitrogen is 196 Round to the nearest hundredth as needed.)

Answer the following for the given quadratic function. f(x) = x2 + 4x - 12 Does the graph of f open up or down? Up Down What is the vertex (h,k) of f? (h,k) = (Simplify your answer. Type an ordered pair.) Graph f(x) = 2x2 - 3x + 4 by determining whether its graph opens up or down and by finding its vertex, axis of symmetry, y-intercept and x-intercepts, if any. Determine the domain and the range of the function. Determine where the function is increasing and where it is decreasing. The graph opens up. What are the coordinates of the vertex? (Type an ordered pair. Use integers or fractions for any numbers in the expression. Simplify your answer.) The price p and the quantity x sold of a certain product obey the demand equation p = - 1/4x + 90, 0 le x le 360 Express the revenue R as a function of x. What is the revenue if 196 units are sold? What quantity x maximizes revenue? What is the maximum revenue? What price should the company charge to maximize revenue? Express the revenue R as a function of x. R(x) = The rate of a chemical reaction varies, depending on the initial amount of a certain compound. In general the reaction rate, V, can be expressed by the following formula, where k is a positive constant, and a is the initial amount of the compound. V(x) = kx(a - x) The positive constant, k, for one such reaction is 0.7, and the initial amount of the compound, a, is 8. For what value of x is the rate a maximum? The rate is a maximum when x is .

In the following descriptions, wite an expression in terms of the given variable that represents the indicated quantity Complete parts (a) through (g) d. The amount of bacteria after n min if the initial amount of bacteria is q and the amount of bacteria triples every 10 sec (Hint The answer should contain q as well as n) The expression for the amount of bacteria is (Simplify your answer ) e. The temperature t hr ago if the present temperature is 70°F and each hour it drops by 4°F The expression for the temperature is F Simplity your answer) f. Pawers total earnings aner 3 yr if the first year his salary was s dollars the second year it was S4000 higher and the third year it was twice as much as the hst year The expression for Pawe's total earnings is dolla (Simplity your answer g. The sum of four consecutive even whole numbers i the greatest is x The expression for the sum of the four consecutive even whole numbers is (Simpli ty your answer ) 暗 1.:i히 /i ::/ì