Solution:

Six.

There are only five colors, so six socks guarantee that two will be the same color.

Solution:

Karate Kid (car + at + tea + kid)

Solution:

Michelangelo juggles the diamonds across while crossing the bridge.

Solution:

This puzzle has no answer if you are considering this figure in a 2d domain. However if you follow it on a three-dimensional plane, you can do it like shown in the figure given.

Solution:

I am Spice

Explanation:
Spice is hot if you remove first two alphabets then it will become "ice", which is really cold.

Solution:

Old password : altered

New Password : distinct

Solution:

Solution can be verified from the picture below.

Solution:

41312432

Solution:

It can be done in 8 moves as shown in the animated image below.

Solution:

NONE, holes are empty.

Solution:

It has been clearly mentioned that all the boxes are labeled incorrectly. If he opens the Box3, then he will get either Dark Chocolates or Milk Chocolates as it is labeled incorrectly. Let us suppose he finds Dark Chocolates in there. Now since all are labeled incorrectly, Box B A must contain Milk Chocolates and Box B must contain Milk Chocolates and Dark Chocolates.