Use the drop-down menus to identify the types of changes described. baking a cake: smashing a soda can: shredding paper: chopping wood: burning wood:

a) Baking a cake: chemical change

b) Smashing a soda can: Physical change

c) Shredding paper : Physical change

d) Chopping wood: Physical change

e) Burning wood: chemical change

Explanation: Chemical change is defined as a change in which rearrangement of atoms take place and leads to formation of new substances.  

Physical change is defined as a change which leads to change in shape, size or state of the substance changes. No new substance is formed.

a) Baking a cake will result in a chemical reaction to evolve carbon dioxide which leads to rise of dough and thus a chemical change.

b) Smashing a soda can will only result in the shape of can and thus a physical change.

c) Shredding paper will only result in the size of paper and thus a physical change.

d) Chopping wood will only result in the size of wood and thus a physical change.

e) Burning wood will result into formation of carbon dioxide and water and thus a chemical change.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.