Option 1/A (It is the first one)
The following are the answers to the different questions:
<span>The four rows of data below show the boiling points for a solution with no solute, sucrose (C12H22O11), sodium chloride (NaCl), and calcium chloride (CaCl2) (not in that order). Which boiling point corresponds to calcium chloride?
A. 101.53° C
Which of the following solutions will have the lowest freezing point?
D. 1.0 mol/kg magnesium fluoride (MgF2)
Which of the following compounds will be most effective in melting the ice on the roads when the air temperature is below zero?
A. sodium iodide (NaI)
Four different solutions have the following vapor pressures at 100°C. Which solution will have the greatest boiling point?
B. 96.3 kPa
Four different solutions have the following boiling points. Which boiling point corresponds to a solution with the lowest freezing point?
D. 108.1°C</span>
False that atom is the smallest identifiable unit of a compound.
The smallest identifiable unit of a compound is the Element. Element is the one which make up the compound and element is made up by atoms. Example of element is oxygen and hydrogen which make up water (H2O) which is a compound.
Valence électrons = are electrons in the outermost shell that is responsible for the chemical reactions of the atoms
1 CH4 (g) + 2 O2 (g) -----> CO2 (g) + 2H2O(l) ΔH= - 890 kJ
1 mol 2 mol
1) If ΔH has minus, it means "release". We need only "release" choices.<span>
2) From reaction
1 mol </span>CH4 (g) "releases" ΔH= - 890 kJ - We do not have this choice.
2 mol O2 (g) "release" ΔH= - 890 kJ, so
1 mol O2 (g) "release" ΔH= - 445 kJ
Correct answer is B.
