>Her hypothesis is that a combination of
>baking soda and baking powder will produce the highest rise

Combining baking soda and baking powder will usually generate more
gases per mole but it depends how you use it....You just can't dump
the leavening agents in the batter and expect it to do the works...In
fact it may not be able to generate the expected volume of gases....It
may also lead to the cake to rise and fall so you will end up with an
inferior product.



>Through her preliminary research, she has learned about how leavning
>agents produce carbon dioxide bubbles which cause the loaf to rise.

CO2 is not the only agent that enable to dough or cake to rise....in
fact its just one factor, The steam generated is another contributor
of any porous baked product volume.