Two substances each have a temperature of 23 degrees Celcius. After they are combined the temperature rises to 27 degrees Celcius. What evidence proves a chemical reaction occurred?

What drives energy flow and chemical cycling on earth?

In the first law of thermodynamics, angle E = Q - W, what does Angle E stand for? A. The heat added to the system B. The internal energy of the system C. The work done by the piston D. The change in the internal energy of the system

Name 3 different types of technology used in water

How many moles are in 2.10 grams of KCr (SO4) 2 • 12H2O

Which of the following statements is true? A. A producer usually obtains food by hunting other organisms. B. Humans that prepare their own meals are producers. C. A producer must be a plant. D. Consumers depend upon producers for food.

A scientist in London and a scientist in California both conducted independent investigations that produced similar results.

When magnesium combines with oxygen, the reaction involves a. a conversion of protons into electrons. b. sharing of electrons between Mg and O. c. transfer of electrons from Mg to O. d. transfer of electrons from O to Mg.

The activation energy for the reaction no2 (g) + co (g) ⟶no (g) + co2 (g) is ea = 100 kj/mol and the change in enthalpy for the reaction is δh = - 375 kj/mol.

What process transform solar energy into chemical energy?

When the reaction was carried out the calculated theoretical yield for water was 176 grams but the measured yield was 148 grams what is the percent yield