1. Given that 50 grams of ice is heated at -20.0 °C to steam at 135.0 °C.
i. Show the graph of the changes from ice to steam
ii. Calculate the energy needed to change the ice to steam
Please use these values:
Heat of fusion = 334.16 J g¯1
Heat of vaporization = 2259 J g¯1
specific heat capacity for solid water (ice) = 2.06 J g¯1 K¯1
specific heat capacity for liquid water = 4.184 J g¯1 K¯1
specific heat capacity for gaseous water (steam) = 2.02 J g¯1K¯1
2. The voltage of an electrochemical cell depends on the redox reaction occurring in the cell. Given a redox reaction below:
Zn(s) + Pb2+(aq) --> Zn2+(aq) + Pb(s)
Pb2+(aq) + 2 e--->Pb(s)Eº = -0.13V
Zn2+(aq) + 2 e--->Zn(s)Eº = -0.76V
Calculate the E.M.F (Voltage) of the cell
3. For the reaction between Cu and Sn the potentials are given below;
Cu2+(aq) +2e- -----------> Cu(s) Eºcathode = 0.34 (half-cell potential)
Sn(s) -----------> Sn2+(aq) + 2 e- Eºanode = - 0.14 (half-cell potential)
Calculate the E.M.F (Voltage) of the cell
4. Calculate pH given [H+] = 1.4 x 10-5 M
5. Find [H+] if pH = 8.5
6. Given the equation below, how many moles of each reactant were there if 13.7 moles of N2(g) is produced?
4NH3(g) + 6NO(g)→5N2(g) + 6H2O(g) 7.
8. Given the equation below, if 3.87×1023 particles of Sb2S3(s) are reacted with excess Fe(s), what mass of FeS(s) is produced?
Sb2S3(s) + 3Fe(s)→2Sb(s) +3FeS(s)
9. Given the following Unknown atoms with their respective atomic numbers,
X; Atomic number 19,
Y; Atomic number 15,
a. Deduce the identities of the elements X and Y.
b. What are the mass numbers of the two elements X and Y?
c. Calculate the number of Neutrons in the respective elements X and Y
d. Deduce the number of electrons in the respective elements X and Y
e. Give the electronic configurations of the two elements
2 answers