2. How many grams of methane must be burned to produce 2.05 grams of water in the complete combustion reaction? The unbalanced equation for the reaction is: _CH418) + _ 0218) ►_CO2(8) +_ H2O(8)

0.88 g

Explanation:

The balanced reaction equation is;

CH4(g) + 2O2(g) > CO2(g) + 2H2O(l)

Number of moles in 2.05g of water = 2.05g/18g/mol = 0.11 moles

If 1 mole of CH4 yields 2 moles of water

x moles of CH4 yields 0.11 moles of water

2x = 0.11

x = 0.11/2

x= 0.055 moles

Molar mass of methane = 16 g/mol

Mass of methane = 16 g/mol * 0.055 moles

Mass of methane =0.88 g

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.