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Thermochemistry questions

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777888:
I have some Thermochemistry test questions...

1.(Multiple choice) In exothermic rxn, heat is transferred to surroundings because
a)kinetic enery decreases
b)potential energy increases
c)chemical potential energy is converted to heat energy
d)chemical kinetic energy is converted to heat energy
e)none of the above
[would the answer be d? kinetic energy->heat energy?]

2.HCl(aq)+CaO(s)->products
200g of HCl(aq) is react with 3.8g of CaO. Temp. change=3.3C. Determine enthalpy of neturalization.
Calculations:
Surroundings:
q=200x4.18x3.3=2.7588kJ
System:
change in energy=-2.7588kJ
enthalpy of neturalization=-2.7588kJ/mol of CaO (Answer)

Am I right calculating this way? I have 2 questions...
(i)Does the 200g HCl(aq) count as SURROUNDINGS?
(ii)How can I determine the Limiting Reagent?

Thank you for helping :D

777888:
can someone teach me question 2? Thank you!

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