At 298 k, you collect 0.5 l of oxygen over water that has a total pressure of 150 kpa. what is the partial pressure of oxygen. (the partial pressure of water vapor at 298 k is 3.6 kpa).

= 146.4 kPa

Dalton's law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases.

Total pressure = Pgas 1 +Pgas 2+Pgas 3  +

Therefore;

Partial pressure of Oxygen = Total pressure - partial pressure of water vapor

   = 150kPa - 3.6 kPa

  = 146.4 kPa

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.