Acid-base indicator changes color based on pH.
drop some in a solution n watch the color changes. different indicators show different colors at different pH. they usually have standard colors for comparison.
From a Chemistry perspective it is the electron at 1/1800th the mass of a proton or neutron.
55 m=180.446 ft.
7500/180.446= approx. 41.56 minutes
5.5 moles
2.0=x/2.75
2.0*2.75= x/2.75 (2.75)
5.5=x
