Astrip of magnesium metal having a mass of 1.30 g dissolves in 150. ml of 5.00 m hcl (specific gravity = 1.10); products of the reaction are magnesium chloride and hydrogen gas. the hcl is initially at 22.0°c, and the resulting solution reaches a final temperature of 52.0°c. the heat capacity of the calorimeter in which the reaction occurs is 345 j/°c. calculate δh (in kj/mol) for the reaction under the conditions of the experiment, assuming the specific heat of the final solution is the same as that for water (4.184 j/g°c).

Explanation:

The given data is as follows.

  Mass of Mg = 1.30 g,   Molarity = 5 for HCl,        Volume = 150 mL

   Density = 1.1 g/mL

  Change in temperature (dT) =

              = 345

Hence, the energy balance will be as follows.

Moles of Mg =

                 =

                 = 0.05349 mol of Mg

                      =

                      = 10350  J

                         =

                         = 20710.8

              = (20710.8 + 10350) J

                  = -31060.8 J

Therefore, calculate the value of  of the reaction as follows.          

                      = -580684.24 J/mol

or,                        (as 1 kJ = 1000 J)

Thus, we can conclude that value of  of the reaction under given conditions is -580.68 kJ/mol.

it’s C

Explanation:

A distant luminous object travels rapidly away from an observer.