Yes! The Volume 1 Answer Key, which was available for sale on our website until January 2020, has the answers for Lessons 1-7 and 8-15. When we first published the 2nd Edition of Essentials, all 15 lessons were in one book.
Learn more about the 2nd Edition of Essentials here.
UPDATE: In January 2020 the Essentials Answer Keys were split in two products to match how the Essentials Student Workbooks are published.