Table of Contents
Enthalpy Change Definition ; s ;Hess’s Law
The enthalpy change definition is the change in enthalpy that is associated with a chemical or physical process. Enthalpy is a thermodynamic state function that is equal to the internal energy of a system plus the product of its pressure and volume.
The sign of the enthalpy change indicates the direction of the change. A positive enthalpy change indicates that the system has gained energy, while a negative enthalpy change indicates that the system has lost energy.
S is a symbol for entropy. Entropy is a measure of the disorder of a system. A positive entropy change indicates that the system has become more disordered, while a negative entropy change indicates that the system has become more ordered.
Hess’s law states that the enthalpy change for a process is the same regardless of the path that is followed between the initial and final states.
Aim
of the study was to investigate the association between red meat intake and all-cause and cause-specific mortality.
The study cohort consisted of 53,788 US health professionals who were free of cardiovascular disease and cancer at baseline in 1986. Red meat intake was assessed by a food frequency questionnaire.
There were 26,214 deaths during follow-up. The hazard ratios for all-cause mortality for the highest vs. lowest quartiles of red meat intake were 1.23 (95% CI: 1.10, 1.37) for unprocessed red meat and 1.27 (95% CI: 1.13, 1.43) for processed red meat.
The hazard ratios for cause-specific mortality were 1.16 (95% CI: 0.99, 1.36) for cardiovascular disease, 1.51 (95% CI: 1.22, 1.87) for cancer, and 1.23 (95% CI: 0.99, 1.53) for other causes.
The study found that higher red meat intake was associated with increased all-cause and cause-specific mortality.
Explanation
The given statement is “The product of two consecutive negative integers is negative.”
This statement is true. For example, the product of -2 and -1 is -2, and the product of -3 and -4 is -12.
Required Materials to Perform Experiment
To perform the experiment, the following materials are required:
-A beaker or other container to hold the water
-A stirring rod
-One or more thermometers
-A clock or timer
-A scale
-A container for the ice
-Salt
-A container for the hot water
The steps of the experiment are as follows:
1. Fill the beaker or other container with water and place it on the scale.
2. Add ice to the container.
3. Add salt to the container.
4. Stir the water with the stirring rod.
5. Measure the temperature of the water with the thermometers.
6. Record the data.
7. Compare the results.
Precautions to be TakenWhile Handling Sulfur
Sulfur is poisonous and can cause skin and respiratory irritation. It is also a fire hazard.
