22: An alloy 20g made up of (AL, Zn and cu) is dipped in an excess 'hydrochloric acid.
Knowing that the percentage by mass of Al was
27% and 6.6 g of residue were
obtained at the end of the reaction.
a. Indicate the redox Couples
b. Compute the mass of each metal
c. Write the half reaction that took place.
d. Deduce the over all equations
e. Compute the volume of the liberated
AL:27 Zn:65 Vm:24
f. Arrange the above couples on the electro
chemical classification

7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation. 8. when a 2.5 mol of sugar (c12h22o11) are added to a certain amount of water the boiling point is raised by 1 celsius degree. if 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? show all calculations leading to your answer or use 3 – 4 sentences to explain your answer. 9. if 5.40 kcal of heat is added to 1.00 kg of water at 100⁰c, how much steam at 100⁰c is produced? show all calculations leading to an answer. 10. the freezing of water at 0⁰c can be represented as follows: h2o (l) ↔ h2o(s) the density of liquid water is 1.00 g/cm3. the density of ice is 0.92 g/cm3. in 3 – 4 sentences explain why applying pressure causes ice to melt.

Why does earth rotate? because earth is formed from cold gases collapsing due to gravity because the matter in the nebula that formed earth was spinning because earth forms more than 99% of the mass of the solar system because the hydrogen atoms inside the nebula fused to form helium

Neutral atoms of argon, atomic number 18, have the same number of electrons as each of the following items except: cl- s -2 k+ ca +2 ne