8.1 In Reaction 1, platinum (Pt) acts as a catalyst - NSC Physical Sciences - Question 8 - 2016 - Paper 2
Question 8
8.1 In Reaction 1, platinum (Pt) acts as a catalyst.
What NAME is given to the energy that a catalyst changes in a chemical reaction?
8.2 Reaction 2 reaches equili... show full transcript
Worked Solution & Example Answer:8.1 In Reaction 1, platinum (Pt) acts as a catalyst - NSC Physical Sciences - Question 8 - 2016 - Paper 2
Step 1
What NAME is given to the energy that a catalyst changes in a chemical reaction?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The energy that a catalyst changes in a chemical reaction is called the activation energy.
Step 2
Is the reaction EXOTHERMIC or ENDOTHERMIC? Give a reason.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The reaction is exothermic because the enthalpy change (∆H) is negative (-149.1 kJ), indicating that heat is released during the reaction.
Step 3
Write down TWO changes that must be made to increase the YIELD of NO₂.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Increase the pressure in the reaction system.
Increase the temperature of the reaction.
Step 4
What is the value of ∆H per mole of NO₂ formed?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The value of ∆H per mole of NO₂ formed is -74.55 kJ.
Step 5
Write down the NAME of the type of reaction between an acid and a base.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The reaction between an acid and a base is called a neutralisation reaction.
Step 6
Which particle (PROTON or ELECTRON) is transferred during the reaction mentioned in QUESTION 8.3.1?
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The particle that is transferred during the reaction is a proton.
Step 7
Calculate the percentage purity of the ammonium nitrate sample.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To calculate the percentage purity:
Calculate the moles of NH₄NO₃:
Given: 0.204 g of NH₄NO₃.
Molar mass of NH₄NO₃ = 80 g/mol
Moles of NH₄NO₃ = ( n = \frac{0.204}{80} = 0.00255 , \text{mol} )
