Using the standard entropy values: C2H4(g), S° = +219.8 J mol-1 K-1 H2(g), S° = +130.6 J mol-1 K-1 C2H6(g), S° = +229.5 J mol-1 K-1 calculate the standard entropy change, ∆S°, for the reaction: C2H4(g) + H2(g) → C2H6(g)

Seawater contains approximately 3.5%nacl by mass and has a density of 1.02 g/ml. what volume of seawater contains 7.5 g of sodium?

What are the primary responsibilities of a chemical engineer involved in "r& d"? develop large scale manufacturing operations discover new products and processes training of new chemists determine products needed by consumers

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.