First, we have to see how K2O behaves when it is dissolved in water:
K2O + H20 = 2 KOH
According to reaction K2O has base properties, so it forms a hydroxide in water.
For the reaction next relation follows:
c(KOH) : c(K2O) = 1 : 2
So,
c(KOH)= 2 x c(K2O)= 2 x 0.005 = 0.01 M = c(OH⁻)
Now we can calculate pH:
pOH= -log c(OH⁻) = -log 0.01 = 2
pH= 14-2 = 12
An endothermic reaction needs energy to proceed, such energy is usually taken from the environment surrounding the reaction. In the typical case this energy is expressed as heat. Heat is an state of atomic activity, that energy is transferred to an ENDOthermic reaction so the initial threshold of reaction is overcome and the final reaction can occur.
342.14 g/mol
Molar mass of Al= 26.98
Molar mass of S=32.06
Molar mass of O=16.00
(26.98)2+(32.06+(16.00×4))3=342.14
Since you provide no options, Henry Moseley measured a property linked to Periodic Table position. After his revisions to the periodic table, Atomic number became more meaningful and the three pair of elements that seemed to be in the wrong order could be explained
Everywhere
Hope that helps and good luck
~May