Summary
Igsce chemistry 0620 important chapters summary
- Course
- Institution
Outlined notes from each main topic
[Show more]
Seller
Follow
marwahimran57
Content preview
, Test for presence of water CH15if water present if water present
Cobalt (11) chloride paper
& anhydrous copper (11) sulfate
changes from blue to pink changes from white to blue
Tests for purity of water
pure substances have > pure water melts at o
a set mp/bp
> pure water boils at 100
impurities
> lower the melting point of ice
> increase the boiling point of water
Distilled water consists water molecules only , it has no impurities
unlike tap water (has dissolved solids like calcium salts d impurities
like chloride and aluminium ions) Thus to get accurate results
.
distilled water is used in practical chemistry
water from natural resources (rivers & lake)
contain : dissolved metal & plastics - sewage
Oxygen compounds a
↓
harmful >
-
nitrates from >
- phosphates from
microbes fertilisers fertilisers detergent
Benefical substances
in natural sources of water
>Dissolved Oxygen for aquatic life (breathing
-metal compounds provide essential minerals for growth
of plant/animal
,Harmful substances
in natural sources of water
> some metal (from industrial waste) can be toxic
compounds
>
Non-biodegradable plastic harm aquatic life
-
sewage contains harmful microbes that cause disease
> Nitrates& phosphates encourage growth of algae
.
Respiration of algae leads to deoxygenation of water
& damage to aquatic life/eutrophication)
Purification of domestic water ① screening
② coagulant
water passed thru ③ sedimentation
a metalgrid screen ① powdered carbon
cremoves large solids ( ⑤ filtration
↓ ⑥ chlorination
coagulants make fine SC
SC
particles dirtd impurities
of
= C
to clump together
↓
clumped particles
settle to bottom of
tank (sedimentation)
↓
Powdered carbon
removes unpleasant taste
&
odova chlorine added to kill
microbes & prevent
water seeps thry water-borne diseases
sand a gravel layers Cchlorination)
to remove fine
Cfiltration) parties
, Fertilisers (Ns P . K)
are chemical compound containing plant nutrients which are
essential for plant growth
>
- makes them grow faster
F
Fertilisers
>
- increases crop yield
18 -
24 - 12
Nitrogenous fertilisers
contains compounds that produce
ammonium/nitrate ions
Air around earth is called atmosphere
>
Atmosphere protects earth from excessive radiation of sun
and keeps earth warm
composition of clean dry air
~
Nitrogen 78 %
Oxygen 21 %
other gases remaining
(noble gas : argon
(CO2)
first calculate
% of oxygen in the
air
then subtract or
add according
whichever value
ur given
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller marwahimran57. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75619 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now