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Chemistry (essay ) *8:30Am–10:00am* Chemistry (objectives) *10:00 am —11:15

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_chemistry (essay )…….._
*8:30Am–10:00am*
Chemistry (objectives)
*10:00 am —11:15
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Chemistry Obj
1-10: ABDCBCABAC
11-20:DACBBACCAA
21-30: CBCDCDAAAB
31-40: AABACBABAA
41-50: DBBDCBCCDB
4aii)
Na2SO3(aq) + 2HCl(aq)—–>2Nacl(aq)+H2O(s)+SO2(q)
4aiii)
dry the gas evolved by passing it through H2SO4 and collect it by downward delivery
4aiv)
because it is denser than air

4bi)
Dalton’s law of partial pressure states that in a mixture of gases, which do not react chemically together, a gas will exert a partial pressure, which is the pressure, it will exert if it is kept alone in the vessel.
4aii)
Na2SO3(aq) + 2HCl(aq)—–>2Nacl(aq)+H2O(s)+SO2(q)

4aiii)
dry the gas evolved by passing it through H2SO4 and collect it by downward delivery

4aiv)
because it is denser than air

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1 a )

Fermentation is the chemical breakdown of a substance by bacteria , yeasts , or other microorganisms , typically involving effervescence and the giving off of heat.

1 aii )

disastase

1 b )

i ) colour change

ii ) end point

1 c )

1 mole

c = n / v = 1 . 0 moldm ^ – 3

V = 10 cm ^ 3 = 0 . 01 dm ^ 3

n = cv= 1 . 0 moldm ^ – 3 * 0 . 01 dm ^ 3

n = 0 . 01 mol of H 2 SO 4

x – – – > 0 . 01 mol of H 2 SO 4

x = 56 * 0 . 01 / 1 = 0 . 56 g

mass unreacted = ( 5 – 0 . 56 ) g = 4 . 44 g

1 di )

copper ( ii ) tetraoxsulphate ( iv)

1 dii)

dyes

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2 ai )

collision theory state that for a reaction to occur it is necessary for the reacting species ( atoms or molecules ) to come together or collide with one another .
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1ai)

Fermentation is the chemical breakdown of a substance by bacteria, yeasts or other microorganisms , typically involving effervescence and the giving off of heat.

1aii)

oli silicon dioxide

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Section B

2a.

The collision theory states that when suitable particles of the reactant hit each other, only a certain percentage of the collisions cause any noticeable or significant chemical change; these successful changes are called successful collisions. The successful collisions must have enough energy, also known as activation energy , at the moment of impact to break the preexisting bonds and form all new bonds. This results in the products of the reaction. Increasing the concentration of the reactant particles or raising the temperature, thus bringing about more collisions and therefore many more successful collisions, increases the rate of reaction.

4b) Dalton’s law of partial pressure states that in a mixture of gases, which do not react chemically together, a gas will exert a partial pressure, which is the pressure, it will exert if it is kept alone in the vessel
1a)
Fermentation is the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat.
1aii)
disastase

1b)
i)colour change
ii)end point

1c)
1mole
c=n/v=1.0moldm^-3
V=10cm^3=0.01dm^3
n=cv=1.0moldm^-3*0.01dm^3
n=0.01mol of H2SO4
x—>0.01mol of H2SO4
x=56*0.01/1 = 0.56g
mass unreacted = (5-0.56)g=4.44g

1di)
copper (ii) tetraoxsulphate(iv)
1dii)
dyes
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