thermochemistry

During chemical reactions, the chemical energy in the reactants an be changed into other forms, into heat energy?

• true

• false

what is the unit of measuring energy?

• Joules, J

• Kj/m

• KWatt

• mol

what is the meaning exothermic reaction.

• heat is released to the surrounding

• heat is absorbed from the surrounding

Surrounding do not involve in the reactions, Surrounding included (4 answers)

• thermometer

• air

• container which holds the reactants and the products

• solvent in which the reactions are taking place

• reactans and products

thermochemistry is

• the study of heat released only

• the study of changes in heat energy which take place during chemical reactions

• the study of heat absorbed only

• the energy level diagram

in an endothermic reaction reaction,

• The temperature of the surroundings increases.

• The reaction container becomes hot.

• Energy changes from chemical energy

  to heat energy.

• The temperature of the surroundings decreaces

in an exothermic reactions, (3 answers)

• The temperature of the surroundings increases.

• The reaction container becomes hot.

• Energy changes from chemical energy

  to heat energy.

• The reaction container become cold

EXAMPLES OF EXOTHERMIC REACTIONS ,

• Thermal decomposition of carbonate salts

• Neutralization reactions

• Thermal decomposition of nitrate salts

• Dissolving of ammonium or potassium salts in water

when a piece of magnesium ribbon is added to some dilute hydrochloric acid in a test tube, a reaction occurs and the test tube becomes hot. the type of reaction is.....

• exothermic reaction

• endothermic reaction

Energy level diagram for endothermic reaction

• •The energy of the products is higher than the energy of the reactants.

• •The energy of the products is lower than the energy of the reactants.