Buffers are usually of three types: Acidic buffers: They consist of a weak acid and its salt of a strong base. Th â¦ ey keep the pH constant in the acidic range.Basic buffers: They consist of a weak base and its salt of a strong acid.
I always go with SPF 50+. But, to be honest, there is not *that* much difference on a daily basis from SPF 25 to SPF 50: To figure out your level of protection, divide 1 by the SPF number.That equals the percentage of rays that are allowed to pass through. So SPF 25: 1/25 = 4% of rays pass through.SPF 50 = 1/50 = 2% of rays pass through. always go with SPF 50+. But, to be honest, there is not *that* much difference on a daily basis from SPF 25 to SPF 50: To figure out your level of protection, divide 1 by the SPF number.
Given that Ka for HF is 6.3 Ã 10-4 at 25 Â°C, what is the value of Kb for F- at 25 Â°C? Kb=? Given that Kb for CâHâNHâ is 1.7 Ã 10-9 at 25 Â°C, what is the value of Ka for CâHâNHâ at 25 Â°C? Ka=?