What is the concentration of K+ ion in solution, in mmol/L? Mass K2Cr2O7 = 2.4 g
Mass water = 310 g
Amount K2Cr2O7 = 8.2 × 10-3 mol
Molality = 0.026 mol/kg
Mole fraction K2Cr2O7 = 4.7 × 10-4
Concentration of K2Cr2O7 = 26 mmol/L

okay hmmm hold up my boy I gotta think for a sec

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.