Do we need a detailed intinerary for visa application?

We are travelling to China in late October after meeting up with friends in Hong kong. The friends who live in Hong Kong are trying to arrange a trip over there to China. We do not have a proper itinerary as they are still checking it out and may not have a final one before we leave here for London at the beginning of October. Will we still be able to get a visa without this information? Is the single entry only valid for 6 days?