How many grams of methane (ch4) does it take to make 16.5g of h2o according to the reaction shown below? ch4 + 202 co2 + 2h2o

 The  number of grams  of methane  that it take to make 16.5 g   of H2o is  7.33 g of methane

  calculation

CH₄  + 2O₂ → CO₂  +2H₂O

step 1:  find the  moles of H₂O

moles = mass÷  molar mass

from periodic table the  molar  mass  of H₂O=  [(1 x2) +16]  = 18  g/mol

moles  = 16.5 g÷ 18 g/mol =0.9167  moles

step 2 :  use the  moles ratio to determine  the moles of CH₄

 CH₄ :H₂O  is  1:2 therefore the  moles of CH₄  = 0.9167 x 1/2 =0.4584  moles

Step 3:  find mass  of CH₄

mass =  moles x  molar mass

from periodic table the  molar mass  of CH₄  = [12+ (1 x4)] = 16 g/mol

mass = 0.4584  moles   x 16 g/mol = 7.33 g

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