\(n_{CH_4}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\\ PTHH:CH_4+2O_2\underrightarrow{t^o}CO_2\uparrow+2H_2O\\ \left(mol\right)....0,25\rightarrow.......0,25\\ PTHH:CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3\downarrow+H_2O\\ \left(mol\right)....0,25\rightarrow..0,25...........0,25\\ a,m_{CaCO_3}=0,25.100=25\left(g\right)\\ c,m_{Ca\left(OH\right)_2}=0,25.56=14\left(g\right)\\ C\%_{Ca\left(OH\right)_2}=\dfrac{14}{200}.100\%=7\%\)