Aresearcher claims that increasing temperature by 10 degrees will double the rate of an enzyme-catalyzed reaction. to test this, he designed an experiment. for each tube, the researcher will measure the rate of product formation

which best justifies the inclusion of tube 5 as a control?

it will provide a measurement of product formation in the absence of the substrate

it will provide a measurement of product formation in the presence of a denatured enzyme

it will show the effect of doubling the amount of substrate on the rate of product formation

it will show the effect of increased enzyme activity on the rate of product formation

It will provide a measurement of product formation in the presence of a denatured enzyme

Explanation:

For any experimental research study, it is a common practice to have sets of experimental runs as well as a control. The main essence of the control is to investigate the effects of a given substance such as an enzyme on the experimental conditions. This is done by comparing the experimental results in the presence of an enzyme with the results in the absence of an enzyme.

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.