Answer: The chemical equation for the formation one mole of 
from its elements in their standard states is 
Explanation:
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
The chemical equation for the formation one mole of from its elements in their standard states is:
where (s) represents solid state and (g) represents gaseous state.
Answer:
Group 1 (or IA)
Explanation:
If element X is a halogen, then it belongs to the group 17 (or VIIA, under a different notation).
For each extra unit of atomic number, the group number increases by 1. That means that the X+1 element would belong to the group 18 (or VIIIA). <em>The X+2 element would thus belong in the group 1 </em>(or IA) one period higher (higher as in numeric value, not as in position in the periodic table).
Answer:
267.57 kPa
Explanation:
Ideal gas law:
PV = n RT R = 8.314462 L-kPa/K-mol
P (16.5) = 1.5 (8.314462)(354) P = 267.57 kPa
That is correct c
Explanation
