Answer:a number of people or things that are located close together or are considered or classed togethe
Explanation:
The chemical equation for this reaction is this:
CO2 + 4H2 = CH4 + 2H2O
from the equation, the mole ration of CO2 to CH4 is ratio 1:1
and CH4 = 25.1
The mole ratio of H2 to H2O is 4:2
therefore, mole of H2 = 19.1* 4/2 = 38.2
The moles of methane produced is 38.2 moles
Answer: b. common ion effect
Explanation: because the saturated ionic compound (the lead II chloride) precipitated when a soluble compound (sodium chloride) was added. The solutions had an ion in common causing one to precipitate. Therefore it is b.