You can find the solutions for the exercises in each chapter of the Heinemann Edexcel C1 textbook in pdf format below:

All C1 Solutionbank
C1 Chapter 1
C1 Chapter 2
C1 Chapter 3
C1 Chapter 4
C1 Chapter 5
C1 Chapter 6
C1 Chapter 7
C1 Chapter 8
C1 Practice Paper
C1 Review Exercise 1
C1 Review Exercise 2