Asolution of ammonia has a ph of 11.8. what is the concentration of oh– ions in the solution?

                 [OH⁻]  =  6.31 × 10⁻³ M

SOlution:

Step 1: Calculate pOH as,

                          pH  +  pOH  =  14

As, pH = 11.8

So,

                          11.8  +  pOH  =  14

Or,

                          pOH  =  14 - 11.8

                         pOH  =  2.2

Step 2: Calculate [OH⁻],

pOH is related to [OH⁻] as,

                          pOH  =  - log [OH⁻]

Putting value of pOH,

                          2.2  =  -log [OH⁻]

Solving for [OH⁻],

                          [OH⁻]  =  10⁻²'²                       ∴ 10  =  Antilog

                          [OH⁻]  =  6.31 × 10⁻³ M

The answer would be

4- c, because all matter stays the same no matter what. it is still there. 5- b, because matter is known as mass. 6-c because, flammability is a chemical property. malleability is changing the shape of an object.