|
As
per
Indian
Standard
First
revision
of
the
year
1951
by
the
Inorganic
chemicals
sectional
committee,
Sodium
Dichromate
contents
was
raised
to
98.5%
and
the
limits
of
impurities
of
Sulphates
and
calcium
compounds
and
the
limit
of
free
combined
water
were
reduced.
In
the
second
revision,
requirements
of
the
matter
insoluble
in
water
and
PH
were
added
in
order
to
ensure
absence
of
chromate
in
dichromate.
In
the
present
revision
the
limit
of
sodium
dichromate
has
been
further
upgraded
to
99.00%
and
the
limit
of
moisture
has
been
changed
to
13.00% |
