Answer:
Rb+
Explanation:
Since they are telling us that the equivalence point was reached after 17.0 mL of 2.5 M HCl were added , we can calculate the number of moles of HCl which neutralized our unknown hydroxide.
Now all the choices for the metal cation are monovalent, therefore the general formula for our unknown is XOH and we know the reaction is 1 equivalent acid to 1 equivalent base. Thus we have the number of moles, n, of XOH and from the relation n = M/MW we can calculate the molecular weight of XOH.
Thus our calculations are:
V = 17.0 mL x 1 L / 1000 mL = 0.017 L
2.5 M HCl x 0.017 L = 2.5 mol/ L x 0.017 L = 0.0425 mol
0.0425 mol = 4.36 g/ MW XOH
MW of XOH = (atomic weight of X + 16 + 1)
so solving the above equation we get:
0.0425 = 4.36 / (X + 17 )
0.7225 +0.0425X = 4.36
0.0425X = 4.36 -0.7225 = 3.6375
X = 3.6375/0.0425 = 85.59
The unknown alkali is Rb which has an atomic weight of 85.47 g/mol
Second law of thermodynamics states entropy of the universe is always increasing. entropy always increases in a spontaneous process .
option B) second law of thermodynamics
for example if we keep a hot cup of coffee the heat is lost to surrounding and entropy( randomness increases) since it is a natural process entropy of universe increases.
Answer:
THERE IS NOTHING MENTION HERE HOW CAN ANYONE KNOW ABOUT IT?]
Explanation:
Answer: Option (d) is the correct answer.
Explanation:
An atom or element which has the ability to readily gain an electron will have high electronegativity.
Both Beryllium and Calcium are alkaline earth metals and hence they are electropositive in nature.
Whereas both iodine and nitrogen are electronegative in nature. But across the period there is an increase in electronegativity and down the group there is a decrease in electronegativity.
Nitrogen belongs to period 2 and iodine belongs to the bottom of group 17. Thus, we can conclude that nitrogen is more electronegative than iodine.
