WorksheetsChem-is-try Challenge 27
Total questions: 7
Worksheet time: 14mins
A Born-Haber cycle for calcium oxide is shown in the diagram above.
Which enthalpy changes have negative values?
p, t, w
p, v, w
q, s, u
t, v, w
The thermochemical equation for the neutralisationS reaction of sulphuric acid by aqueous solution of potassium hydroxide is given below
2KOH(aq) + H2SO4(aq) → K2SO4(aq) + 2H2O(l)
ΔH0= -114 kJ
What is the standard enthalpy of neutralisation, in kJ mol-1, for the reaction between nitric acid with an aqueous solution of sodium hydroxide?
-28.5
-57
-114
-228
Which compound has the lowest lattice energy?
CaCl2
CsCl
K2O
MgCl2
The half-cell equation and the standard reduciton potential for X and Y are shown below
X2+(aq) + 2e- ↔ X(s) +0.34V
Y+(aq) + e- ↔ Y(s) +0.80V
What is the e.m.f. of the cell constructed from the two half cells?
-1.14V
-0.46V
+0.46V
+1.26V
The Nernst equation is written as
Ecell = E0cell - 0.059/n logQ
For the reaction Mg(s) + 2H+(aq) → Mg2+(aq) + H2(g), Q may be expressed as
[Mg][H+]2[Mg2+]
[Mg][H+]2[Mg2+]pH2
[H+]2[Mg2+]pH2
[Mg2+]PH2[H+]2
An electrochemical cell is shown in the diagram above.
Standard reduction potential for X is -0.76V. Which statement is NOT true of the above cell?
Hydrogen is a weaker reducing agent than X
The cell diagram is Pt(s), H2(g)∣H+(aq)∥Xn+(aq)∣X(s)
The voltmeter reading at standard condition is 0.76V
The equation for the overall cell reaction is 2X(s) + 2nH+(aq) → 2Xn+(aq) + nH2(g)
Which statement explains why graphite powder is spread onto plastic material first in plastic electroplating process?
Graphite is an electric conductor
Plastic becomes more resistant to heat
Plastic electroplating process is accelerated
Graphite can form chemical bond with plastic
