Read the passage and answer the next two questions. Scientists created energy diagrams to correspond to various chemical reactions. These
energy diagrams represented the energy changes of various reactants and products as
the reactions take place. These diagrams showed that endothermic reactions absorb
energy from their surroundings while exothermic reactions released energy into their
surroundings. The diagrams also showed the activation energies associated with
various reactions.
14. Observe the graph. Which of the following statements is correct?
Modeling an Endothermic Reaction
I
Energy
Direction of reaction
|
A. The energy of the reactants is lower than the energy of the products.
B. The energy of the reactants is higher than the energy of the products.
C. The energy of the reactants is equal to the energy of the products.
D. There is no energy absorbed during this reaction.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.

може ли да зареждате повече информация, моля

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied