Which of the following statements describe physical properties and which describe chemical properties? (a) iron has a tendency to rust. (b) rainwater in industrialized regions tends to be acidic. (c) hemoglobin molecules have a red color. (d) when a glass of water is left out in the sun, the water gradually disappears. (e) carbon dioxide in air is converted to more complex molecules by plants during photosynthesis.

Explanation:

a ) iron ha tendency to rust       --  chemical property ,because it involves chemical reaction with water and air

b) Rainwater in industrialized regions tends to be acidic chemical property ,because it involves chemical reaction with bases or metals etc

c) Hemoglobin molecules have a red color   Physical property because it does not involve any chemical reaction

d) When a glass of water is left out in the sun ,the water gradually disappears

Physical property, because the process can be reversed easily so it is a physical change.

e) Carbon dioxide in air is converted to more complex molecules by plants during photosynthesis.Chemical property, because it involves chemical reactions.

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.

the volume increases