Answer:
If some of the stearic-acid hexane solution had evaporated before using it, this would increase Avogadro's number, or the number of atoms per mole. This is because with less hexane in the solution (because only the hexane evaporates), the grams of stearic acid used would be smaller.
Explanation:
Answer: Option (C) is the correct answer.
Explanation:
When the volume of a container is decreased and same number of gas molecules are present inside the container at the same temperature then it means that more number of gas molecules are spread per unit volume.
As earlier when the volume of container was more then the molecules were widely spread inside the container but on decreasing the volume of container, molecules come closer to each other and hence there will be increase in molecules per unit volume.
Atoms in the same group (column) of the periodic table have similar properties. This is because all elements in the same group have the same amount of valence (outer) electrons.
So, any element directly above or below Calcium on the periodic table would have similar properties.
These would be Magnesium, Barium, Strontium, Radium, and Beryllium.
Answer: The enthalpy of formation of 
is -396 kJ/mol
Explanation:
Calculating the enthalpy of formation of
The chemical equation for the combustion of propane follows:
The equation for the enthalpy change of the above reaction is:
![\Delta H^o_{rxn}=[(2\times \Delta H^o_f_{(SO_3(g))})]-[(2\times \Delta H^o_f_{(SO_2(g))})+(1\times \Delta H^o_f_{(O_2(g))})]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28SO_3%28g%29%29%7D%29%5D-%5B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28SO_2%28g%29%29%7D%29%2B%281%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28O_2%28g%29%29%7D%29%5D)
We are given:
Putting values in above equation, we get:
![-198=[(2\times \Delta H^o_f_{(SO_3(g))})]-[(2\times \Delta -297)+(1\times (0))]\\\\\Delta H^o_f_{(SO_3(g))}=-396kJ/mol](https://tex.z-dn.net/?f=-198%3D%5B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28SO_3%28g%29%29%7D%29%5D-%5B%282%5Ctimes%20%5CDelta%20-297%29%2B%281%5Ctimes%20%280%29%29%5D%5C%5C%5C%5C%5CDelta%20H%5Eo_f_%7B%28SO_3%28g%29%29%7D%3D-396kJ%2Fmol)
The enthalpy of formation of is -396 kJ/mol
Chemical Change because if it would be a physical change the physic of the tea would look different but it doesn’t
