The answers are:
11. To honor the restauran's foreign guests, The head chef changed the menu.
2. The living room was decorated in shades of lavender an teal by my mother.
Step-by-step explanation
To change a sentence in English from the active voice to the passive voice:
1. Look at the sentence carefully and determine the subject of the sentence.
2. Determine the object of the sentence.
3. Put the object in the front of the sentence and place the subject towards the end of the sentence.