Hydrogen peroxide will decompose if the bottle is left open, and the resulting release of energy will heat up the solution. which of the following best describes this type of reaction? 1. endothermic 2. exothermic 3. combustion 4. synthesis

Answer is: 2. exothermic.

There are two types of reaction:  

1) exothermic reaction (chemical reaction that releases more energy than it absorbs).  

For example, ΔH(reaction) = -225 kJ/mol; this is exothermic reaction.

2) endothermic reaction (chemical reaction that absorbs more energy than it releases).

Hydrogen peroxide (H₂O₂):

1) have molecular structure.

2) it is higly reactive, it is not physically and chemically stable.

3) has low boiling point (around 150°C), because weak covalent bonds.

4) dissolve in water, because it has polar bond.

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

answersilicon (si); oxygen (o);