The action or process of making a copy of something.
Sulphur trioxide reacts with water to form a solution of sulphuric acid.
The equation describing this reaction is:
SO3 + H2O .............> H2SO4
Based on the above equation, the formula of the compound formed when sulphur trioxide reacts with water is: H2SO4
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances.