Answer:
C. 17 grams.
Explanation:
∵ mass % = [mass of solute/mass of solution] x 100.
mass of solute (NaCl) = ??? g & mass of solution = 140.0 g.
<em>∴ mass of NaCl = (mass %)(mass of solution)/100 </em>= (12.0)(140.0)/100 = <em>16.80 g ≅ 17.0 g.</em>
<span>The correct answer is d. The reaction releases more energy than it absorbs. An example of an exothermic reaction is fire. Connecting the carbon atoms in wood with the oxygen in the air causes flames and gives of heat and light.</span>
Answer:

Explanation:
Incorrect use has resulted in accidents and disfiguring burns. Never leave a methylated spirit appliance unattended. Also make sure that the camping stove or appliance is on a flat surface and that the fuel cannot spill out.
Lets find the electronegativity difference between the bonded atoms;
C-H = 2.6-2.2 = 0.4
C-F = 4.0-2.6 = 1.4
F-F = 4.0-4.0 = 0
H-O = 3.4-2.2 = 1.2
Here the electronegativity difference is highest for C-F bond hence C-F bond is most polar.