Asample of impure tin of mass 0.526 g is dissolved in strong acid to give a solution of sn2 . the solution is then titrated with a 0.0448 m solution of no3−, which is reduced to no(g). the equivalence point is reached upon the addition of 3.67×10−2 l of the no3− solution.
find the percent by mass of tin in the original sample, assuming that it contains no other reducing agents.

55.7%

Explanation:

The reaction that takes place is:

With the volume and concentration of NO₃⁻ solution, we can calculate the moles of Sn²⁺ that reacted:

Now we convert moles of Sn to mass, using its atomic weight:

Finally we calculate the percent by mass of Sn:

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.