Which of the following changes can be reversed by changing temperature? (check my work)?

Question

a) dew condensing on leaf
b) an egg turning hard when it is boiled
c) ice cream melting
d) a spoonful of batter cooking on a hot griddle

my approach:
a) physical change
b) no physical change
c) no
d) no

(i will award best answer)

Answer 1

A is reversible. Most reversible temperature changes are to elemental substances and simple compounds.

Many say C is, but ice cream will not be the same after refreezing. All you will have is frozen cream and it will not be nummy nummy. The actual chemical makeup of the material will be unchanged though, so technically this is reversible. Certainly, any subsequent melting and freezing will not change it any further.

Answer 2

A and C can be reversed, because they are changes in state

B and D cannot be changed as they involve chemical changes.

B - Albumen coagulating under heat to solidify

D - Batter cooking and solidifying on the griddle

Answer 3

a and c are physical changes and could be reversed.

b and d are chemical changes and can not be reversed.

You can refreeze ice cream and dew can evaporate.

Answer 4

if ice cream melts and refreezes it's kinda ice cream though with a lot of freezer burn. melting and freezing are physical changes