Transcript Exothermic and Endothermic Reactions Practical Solutions

Endothermic and Exothermic
Reactions Practical
Working and Solutions
1. Mg(g) + 2HCl(aq)  MgCl2(aq) + H2(g)
2. q (or ∆H) = mcΔT = (25+0.1)x4.18xΔT
3. n(Mg) = 0.1/24.31 = 4.11x10-3 moles
4. q (per mole)= (25+0.1)x4.18xΔT
n
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6. Ba(OH)2(s) + 2NH4NO3(s)  Ba(NO3)2(aq) + 2NH3
(aq) + H2O(l)
7. Liquid has been formed a reaction that has
increased disorder (more energy). Solid and Solid
going to liquid.
8. Ammonia gas produced. Turns red litmus paper
blue.
9. Enthalpy of products is more than the enthalpy
of reactants.
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11. 1st reaction NaCO3(s)  Na2O(s) + CO2(l)
(Endothermic – thermal decomposition)
2nd reaction Na2O(s) + H2O(l)  2NaOH(aq)
(Exothermic)
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13. Zn(s) + CuSO4(aq)  ZnSO4(aq) + Cu(s)
14. q (or ∆H) = mcΔT = (25+0.1)x4.18xΔT
15. c(CuSO4) = n/v
n(CuSO4) = c x v = 0.5 moldm-3 x 0.05dm3 = 0.025
moles CuSO4
n(zinc) = 3/65.37 = 0.046 moles Zn  excess
16. q (per mole)= (50+3)x4.18xΔT
0.025
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