We will be applying for our visa from Hanoi. how likely it is that we will be granted two months?

My friend and I are hoping to spend two months in China starting on the 15th June. Also, if we apply for the two month visa, and they were only willing to give us one month, would the reject it and expect us to reapply or would they just grant us 1 month? That might seem a bit convoluted but I can't think of a better way to phrase it!
Thanks
Jack