Zinc metal reacts with hydrochloric acid to produce hydrogen gas and an aqueous solution of zinc(II) chloride. What is the reducing agent in this reaction?

Zinc is the reducing agent.

Explanation:

Zn is the reducing agent because its oxidation state increases from 0 to 2 and hydrochloric acid, HCl is the oxidizing agent because it loses hydrogen ions, H+ based on the following balanced equation:

Zn (s) + 2HCl (aq)  >  ZnCl2 (aq) + H2 (g)

In oxidation, there is the loss of electrons. In reduction, there is a gain of electrons. A nemonic device that might help is LEO (the lion said) GER.

Losses

Electrons

Oxidation

Gains

Electrons

Reduction

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml