Solve: When you mix two substances, the heat gained by one substance is equal to the heat lost by the other substance. Suppose you place 143 g of aluminum in a calorimeter with 1,320 g of water. The water changes temperature by 7 °C and the aluminum changes temperature by -70.00 °C. Water has a known specific heat capacity of 4.184 J/g °C. Use the specific heat equation to find out how much heat energy the water gained (q).

38660.16 J

Explanation:

From the question,

Heat gained by water is given as

Q = cm(Δt) Equation 1

Where c = specific heat capacity of water, m = mass of water, Δt = temperature change of water.

Given: c = 4.184 J/g.°C, m = 1320 g, Δt = 7 °C.

Substitute these values into equation 1

Q = 4.184×1320×7

Q = 38660.16 J

Hence the heat energy gained by the water is 38660.16 J

it have destructive character

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.