Which temperature is called absolute zero

What is the internal energy change of a system when it absorb 15 KJ of heat and does 5 KJ of work

The compound called blue vitriol is

A mixture of two gases are called 'Syn gas'. Identify the mixture.

Which one of the following functional ingredients improves gastrointestinal health
and also calcium absorption ?

Which one is the poorest method of food freezing ?