How many grams of co are in 125 ml of a 0.25 m solution? 0.87 g 1.1 g 14 g 880 g?

   The number of  grams of Co that  are  in 125 Ml  of  0.25 M solution  is  0.87 grams                             

           calculation
find the number of moles
 moles= molarity  x  volume in liters
volume in liters =  125/1000 = 0.125 L
molarity =  0.25 M

moles  is therefore =  0.125 x 0.25=0.0313 moles
 mass  = moles   x molar mass

molar mass of Co= 12 +16  =28g/mol

mass   is therefore =  28 g/mol  x0.0313 moles= 0.87 grams

Yes, endothermic means it turns cold. and some chemical changes include change of tempature.