The reaction 2c2h6 + 7o2 yields 4co2 + 6h2o has a ratio of 2 parts ethane (c2h6) and 7 parts oxygen (o2). how many parts ethane (c2h6) will be needed to react with 21 parts of oxygen (o2)? show your work.

Which statement describes both homogeneous mixtures and heterogeneous mixtures?

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?