55. Aspirin, C, H,O, is prepared by reacting salicylic acid, C. H.Os, with acetic anhydride, C. H.03, in the reaction 2CH40,(s) + CHO,(2) = 2C3H4O, s) + HEO(!) A student is cold to prepare 25.0 g of aspirin. He is also cold that he should use a 50.0% excess of acetic anhydride and expect to get a 65.0% yield in the reaction. How many grams of each reactant should he use? please help, thank u!! :))

Plz me ! 1 which of earths spheres contains most of its mass? a atmosphere b hydrosphere c geosphere* d biosphere 2 erosion and weathering are examples of which types of forces? a constructive forces b destructive forces* c gravitational forces d inertia-related forces 3 which of the following statements about earths atmosphere is true? a earths atmosphere contains 78% water vapor which is essentail to life b earths atmosphere contains 21% oxygen c earths atmosphere contains carbon dioxide which all life forms require d earths atmosphere allows radiation from the sun to pass through it and warm earths surface* 4 the strenght of the force of gravity between two objects is determined by which of the following factors? select all that apply a the messes of the objects* b the distance between the objects* c the volumes of the objects d the surface area of the objects 5 earth and moon are kept in there respective orbits due to the influence of a inertia b gravity c gravity and inertia* d neither gravity or inertia if you answer all questions right i will give

Rank substituents in order of their priority when assigning the e or z label to an alkene. i, ch2i , h, ch2ch2cl, f

The following questions a24 - a26 relate to 100 ml of 0.0150 m solution of benzoic acid (c6h3cooh). ka(c6h3cooh) = 6.4 x 10^-5. what is the ph of the solution after the addition of 1 x 10^-3 moles of naoh? you may assume no volume change to the solution upon addition of the naoh.