A metal rail rusting in damp weather.
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
<h2>Answer : Option D) Solutions of salt and water conduct electricity.
</h2><h3>Explanation :</h3>
The best description of salt is that when they are dissolved in water they dissociate into ions and become electrolytic in nature. This is observed that these solutions of salt will conduct electricity. Dissociation of ions helps the solution to conduct electricity. Usually salts dissociate into respective cations and anions of the salt compound. Most of the salts can be obtained as a product from neutralization reactions.
Answer:
there are 9 orbitals in third shell of a atom
formula to calculate is n²
where n - no of shell
orbitals on axial are 6
