The percent by mass of methanol (MM = 32.04 g/mol) in an aqueous solution is 21.1%. What is the molality of the methanol solution?

Molality of the methanol solution = 8.33 m

Explanation:

Given:

Mass % = 21.1 %

Molar mass of methanol = 32.04 g / mol

Find:

Molality of the methanol solution?

Computation:

Moles of methanol = Mass / Molar mass

Moles of methanol =  = 21.1 / 32.04

Moles of methanol = 0.658

Assume.

Mass of solution = 100 g

Mass of solvent  = 100 -21.1 = 78.9 g  = 0.0789 kg

Molality of the methanol solution = 0.658 / 0.0789

Molality of the methanol solution = 8.33 m

b is the correct

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.