Kf(water) = -1.86 °C/m In a laboratory experiment, students synthesized a new compound and found that when 13.39 grams of the compound were dissolved in 202.1 grams of water, the solution began to freeze at -2.050 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ?

The molecular weight for the compound is 60.1 g/mol

Explanation:

We need to determine the molality of solute to find out the molar mass of it.

We apply the colligative property of freezing point depression:

ΔT = Kf . m . i

If the compound was also found to be nonvolatile and a non-electrolyte,

i = 1.

Freezing T° of pure solvent - Freezing T° of solution = Kf . m

0°C - (-2.05°C) = 1.86°C/m . m

2.05°C / 1.86m/°C = m → 1.10 mol/kg

To determine the moles of solute we used, we can multiply molality by the mass of solvent in kg → 202.1 g . 1kg/1000g = 0.2021 kg

1.10 mol/kg . 0.2021kg = 0.223 moles

Molar mass→ g/mol → 13.39 g / 0.223 mol = 60.1 g/mol

explanation:

i think option no d is the correct answer

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.