BCC -iron with a concentration of carbon initially being 0.1 wt.% throughout is packed in carbon black and then placed in a furnace at 900°C. This effectively makes the concentration of carbon 100 wt.% at the surface. How much time will it take (in seconds) for the concentration of carbon to reach 5 wt.% at 1 mm from the surface of the steel? The diffusion coefficient for carbon in BCC -iron at 900°C is 1.4 x 10-10 m²/s

Consider the reduction reactions and their equilibrium constants. cu+(aq)+e−↽−−⇀cu(s)pb2+(aq)+2e−↽−−⇀pb(s)fe3+(aq)+3e−↽−−⇀fe(=6.2×108=4.0×10−5=9.3×10−3 cu + ( aq ) + e − ↽ − − ⇀ cu ( s ) k =6.2× 10 8 pb 2 + ( aq ) +2 e − ↽ − − ⇀ pb ( s ) k =4.0× 10 − 5 fe 3 + ( aq ) +3 e − ↽ − − ⇀ fe ( s ) k =9.3× 10 − 3 arrange these ions from strongest to weakest oxidizing agent.

If a simple machine aduces the strength of a force, what must be increased? the speed of the input force the work the simple machine performs the size of the simple machine the distance over which the force is applied

Which of the following warnings would an agricultural chemist tell a farmer who wants to recycle his or her own ammonia? recycling ammonia is a difficult process that sometimes takes weeks. recycling ammonia requires a degree in biochemistry or a related field. recycling ammonia can be harmful because it is highly flammable and toxic. recycling ammonia costs too much money considering the price of the necessary chemicals.