Answer:
In water PH+Poh=14. Ph=14-pOH=14-5=9
Explanation:sorry its so long hope this helps
O
H
=
−
log
10
[
H
O
−
]
by definition.
Thus
p
O
H
=
−
log
10
(
1
×
10
−
5
)
=
−
(
−
5
)
=
5
p
H
+
p
O
H
=
14
p
H
=
14
−
p
O
H
=
14
−
5
=
9
When we write
log
a
b
=
c
, we ask to what power we raise the base,
a
, to get
b
; here
a
c
=
b
. The normal bases are
10
,
(common logarithms)
, and
e
,
(natural logarithms)
.
Thus when we write
log
10
(
10
−
5
)
, we are asking to what power we raise
10
to get
10
−
5
. Now clearly the answer is
−
5
, i.e.
log
10
(
10
−
5
)
=
−
5
, alternatively
log
10
(
10
5
)
=
+
5
.
What are
log
10
(
100
)
,
log
10
(
1000
)
,
log
10
(
1000000
)
?
?
You shouldn't need a calculator, but use one if you don't see it straight off.
