In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
You take the grams of CO₂ times Avogadro's number divided by the molar mass.
When the enthalpy value is given, we can calculate how much heat is use or produces in a given equation.
67.6 kCal ---> 67.6 kCal= 1 mol of reaction
1 mol of reaction= 1 mol of CO (based on the coefficient)
so 1 mole of CO gives us 67.6 kCal of heat.
calculation:
1 mol CO
Answer is: d). 1-propanol. Because between two molecules of 1-propanol can for form hydrogen bond, between hydrogen and oxygen in hydroxy group.
1) Chemical formula for propanal is CH₃-CH₂-CH=O. Propanal is a saturated three carbon aldehyde (have a carbonyl center).
2) Chemical formula for propane is CH₃-CH₂-CH₃. Propane is a three carbon alkane (acyclic saturated hydrocarbon).
3) Chemical formula for propanone is (CH₃)₂-C=O. Propanone or acetone is he simplest and smallest ketone.
4) Chemical formula for propanol is CH₃-CH₂-CH₂-OH. 1-propanol is a primary alcohol.
Hydrogen bond is
an electrostatic attraction between two polar groups that occurs when
a hydrogen atom (H), covalently bound to a
highly electronegative atom such as flourine (F), oxygen (O) and
nitrogen (N) atoms.
