Twelve grams of carbon combine chemically with 4 grams of hydrogen to produce a
combustible gas. What is the empirical formula of this gas?
O A. C2H4
© B. CH3
OC. CH
OD. CH

                      Empirical Formula  =  C₁H₄ or CH₄

Explanation:

Data Given:

                     Mass of C  =  12.0 g  

                     Mass of H  =  4 g  

Step 1: Calculate Moles of each Element;

                     Moles of C  =  Mass of C ÷ At.Mass of C

                     Moles of C  = 12.0 ÷ 12.0

                     Moles of C  =  1.0 mol

                     Moles of H  =  Mass of H ÷ At.Mass of H

                     Moles of H  = 4.0 ÷ 1.0

                     Moles of H  =  4.0 mol

                     Moles of O  =  %O ÷ At.Mass of O

                     Moles of O  = 53.924 ÷ 16.0

                     Moles of O  =  3.370 mol

Step 2: Find out mole ratio and simplify it;

                             C                                                     H                                

                            1.0                                                   4.0                              

                         1.0/1.0                                             4.0/1.0                    

                              1                                                      4                  

Hence,

              Empirical Formula  =  C₁H₄ or CH₄

d. temperate deciduous forest

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.