For a particular chemical reaction the rate​ (g/hr) at which one of the reactants changes is proportional to the amount of that reactant present. If y represents the amount of that reactant at time​ t, StartFraction dy Over dt EndFraction equals minus0.7y. If there were 70 grams of the reactant when the process started ​(tequals ​0), how many grams will remain after 4 ​hours?

Amount of reactant after four hours = 4,26 grams

Explanation:

Suppose y denotes the amount of reactant at the time (t)

The given function:

Taking integral on both sides

㏑(y) = -0.7t + c¹

At t = 0 ; y (t) = 70

∴

C = 70

As such;

After four hours, the amount of the reactant is:

Amount of reactant after four hours = 4,26 grams

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.