(No1)
-Physical changes only change the appearance
of a substance, not its chemical composition.
-it’s process that does not cause a substance
to become a fundamentally different substance.
-It involves physical changes.
-Examples : dissolving sugar in water (sugar
molecules are dispersed within the water, but
the individual sugar molecules are unchanged.)
-Boiling water (water molecules are forced
away from each other when the liquid changes
to vapor, but the molecules are still water.
Chemical change xteristics
It’s a process that causes a substance to
change into a new substance with a new
chemical formula.
-it’s also a process involving the breaking or
making of interatomic bonds and the
transformation of a substance (or substances)
into another
-Chemical changes cause a substance to
change into an entirely substance with a new
chemical formula
-Chemical changes are also known as chemical
reactions. The “ingredients” of a reaction are
called reactants, and the end results are called
products.
Examples: iron rusting (iron oxide forms) and
bread rising (yeast converts carbohydrates into
carbon dioxide gase)
1ii)
GASES DENSER DAN AIR IS THROUGH
DOWNWARD DELIVERY
ii)LESS dense,upward delivery
=================
2bi)
Gay Lussac’s Law of Combining Volumes states
that when gases react, they do so in volumes
which bear a simpleratio to one another, and to
the volume of the product(s) formed if
gaseous, provided the temperature and
pressure remain constant.
[10:56am, 17/06/2015] Waec Runz: 4ai) Isomerism: This a phenomenon whereby a compound will have the same
molecular formula but different structural
Formulas. e.g
Butane(C4H10) has two isomers.
CH3-CH2-CH2-CH3.
its has two types :
1)Structural Isomersim
2)Cis-trans Isomersm(Geometric
Isomersm)
4aii)
-they have low melting and
boiling points
-they have a strong odors
-they don’t conduct
electricity well
TYPE D
1-10: CDAAAEABAE
11-20: DDCACDCCAA
21-30: EED – ADBCAE
31-40: DBADDCADAA
41-50: ACBDAADDCB
51-60: ECCDECBBCD
No
1aii)
Gases soluble in water and denser dan air
Downward delivery.
Gas soluble but less dense dan air
Upward delivery.
Gases insoluble and less dense – Collection by water
1bi) HCL gas and ammonia gas
1bii) highly soluble in water
1biii)
==> Compound:
I) Element are chemically combined
II) It is homogeneous
==> Mixture:
I) Are physically combined
II) It is heterogeneous
1ci) An isotope is a form of a chemical element
whose atomic nucleus contains a specific
number of neutron s, in addition to the
number of proton s that uniquely defines
the element.
The nuclei of most atom s
contain neutrons as well as protons. (An
exception is the common form of hydrogen,
whose nucleus consists of a lone proton.)
Every chemical element has more than one
isotope.
1cii)
=> Atomic Mass(x) | 35 , 37
=> R.abundance (f) | 75 + 25 = 100
=> Atomic by R.A(fx) | 2625 , 925
Total of (Fx) = 2625 + 925 = 3550
RAM = 3550/100
= 35.5
“Note: they are in tabular form
The sign (,) means Next line”
1ciii) Hudrogen gas , tetrachloromethane,methane
1civ)
I) High boiling point and Melting points
ii) Soluble in water & insoluble in organic solvent
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