Standard error of AutoCorrelation

CFA Level II Quant
#1

The standard error formula is = std/sqrt (n)

but for autocorrelation the standard error formula is = 1/sqrt(n)

why are we not considering the standard deviation while calculating the standard error of auto-correlation?

Thanks

#2

The standard deviation for the autocorrelation is 1. Think of the observations and the time aspect as normally distributed (e.g. months, quarters, years, etc.)

#3

Does it matter if the autocorrelation is one lag or two lags? i.e. does the 1 become a 2 incase of a two lag autocorrelation?