How can you tell if a chemical reaction occurred?

A. Change in color

B. Created gas

C. Change in Temperature

D. Formed a precipitate

E. All of the above

Combustion of 7.54 g of liquid benzene (C6H6) causes a temperature rise of 50.3°C in a constant-pressure calorimeter that has a heat capacity of 6.27 kJ/°C. What is ∆H for the following reaction? C6H6 (l) + O2 (g) → 6CO2 (g) + 3H2O (l)

Which of the following physical properties of stars are plotted on an HR diagram? Absolute brightness and size Apparent magnitude and mass Apparent magnitude and luminosity Absolute brightness and temperature

Water is a poor conductor of heat. Yet when you heat water in a pan, the surface gets hot quickly, even though you are applying heat to the bottom of the water. Explain.

Do you think people use drugs to heighten consciousness or to escape from it?

For something to be considered an organic macromolecule, what chemical element must be found in it

Acids feel slick or soapy and usually have a bitter taste. True or False

What are two ways in which density has practical importance?

What happens to the density of a fluid when it is cooled?

What is meant by polar molecule?

Which kind of dating can be used to determine the exact age of the rock and which kind of carbon dating is used to compare the ages of rocks?