Kw=[OH-][H+]
1.0X10^-14=[OH-][1.3]
[OH-]=(1.0X10^-14)/(1.3)
[OH-]=7.7
In a solution of HCl, all of the HCl molecules ionize completely in water to form H+ and Cl- ions. Therefore, the concentration of OH- ions in a HCl solution is negligible since there are no OH- ions produced in the dissociation of HCl.
About 13M. You can assume it is 13M if you don't need an exact concentration (like if you need a ~1M HCl solution for an extraction or whatever) but if you need an exact concentration (for a titration, for example) then you will need to standardize your HCl first.
p = -log[H+] = 12.4
13m is 1,300cm
13m is 42 feet 7.81 inches.
If it is: 13m+5n-6m+9n Then simplified it is: 7m+14n
6.5m
1300 of them.
It is 13m
13m
13m(14ft)
13M/year
364