Chemistry exam qs that I didn't get full marks Flashcards

1
Q

Explain why the use of a catalyst reduces energy demand and benefits the environment

A
  • the reaction uses less thermal energy as the catalyst allows the reaction to be finished at lower temperatures so co2 emissions are reduced due to less fossil fuels being used
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2
Q

The rate of reaction between Zinc and HCL can be increased by using a solution of copper (II) sulfate as a catalyst

ii) why is it difficult to classify the solution of copper (ii) sulfate as homogeneous or heterogeneous

A

As copper sulfate can be the same state of one of the reactants e.g. zinc and a different state for another HCL

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3
Q

State an example of a catalyst used by the chemical industry and write the equation for the reaction that is catalysed.

catalyst:
Reaction:

A

there is a number of different ones but im going to use Fe in the harbour process
Catalyst: Fe
Reaction: N2 + 3H2 —-> 2NH3
<——

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4
Q

Explain how increasing temperature increases the rate of reaction, include a labelled sketch of the boltzmann distribution curve (4)

A

(1) labelled axis
(1) 2 curves correctly drawn
(1) labelled which one is temp
(1) increasing temperature means more molecules above activation energy so rOR is increased

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5
Q
A
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6
Q

How many P orbitals are occupied by electrons in a sulfur atom
A) 2
B)4
c)6
D)10

A

c

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7
Q

Magnesium nitrate decomposes when heated :
Mg(no3)2 -> Mg0 + 2NO2+0.5o2
0.00250 mol of magnesium nitrate is decomposed what’s the volume of gas produced at RTP
a0 30cm
B) 60cm
c) 120
d) 150

A

d

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8
Q

Zinc reacts with aqueous silver nitrate as shown in the equation
Zn + 2AgNO3 -> 2AG + Zn(no3)2
0.10g zinc is added to 15cm3 of o.250 mol dm agNo3
what is mass of silver nitrate
0.16
0.20
0.33
0.40

A

0.33g

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9
Q

A sample of gas has a volume of 0.60m3 under a pressure of 200Kpa and at 300k , how many moles of molecules are there?

a) 0.021
b) ).048
21
D) 48

A

D PV=NRT

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10
Q

what would be the reason that an equation would be at homogenous equilibrium

A

as the catalyst was the same state as reactants and the products

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11
Q
A
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12
Q
A
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