True or False?
1) Do Nuclear changes generally absorb more energy than chemical changes.
2) In Exothermic reactions, the reactants have more kinetic energy than the products.
3) If one molecule is involved the rate determining step is called first order.
Is it
1)F 2)F 3)T
Explain?
1) False. To determine whether nuclear changes generally absorb more energy than chemical changes, we need to consider the energy changes associated with each type of change.
Nuclear changes involve the splitting or combining of atomic nuclei, resulting in the release or absorption of a large amount of energy. Examples of nuclear changes include nuclear fission and nuclear fusion. These processes release tremendous amounts of energy, much more than chemical changes.
On the other hand, chemical changes involve the breaking and forming of chemical bonds between atoms. These changes can release or absorb energy, but the energy changes involved are typically much smaller than those in nuclear changes. Chemical reactions are often characterized by the amount of energy transferred in the form of heat, referred to as enthalpy changes.
Therefore, the statement that nuclear changes generally absorb more energy than chemical changes is false. Nuclear changes release more energy than chemical changes.
2) False. In exothermic reactions, the products have more kinetic energy than the reactants. An exothermic reaction is a chemical reaction that releases heat or energy to the surroundings. During such a reaction, the reactant molecules lose energy as the chemical bonds within them are broken. The energy released during bond breaking is transferred to the surroundings as heat, raising the kinetic energy of the products.
In contrast, endothermic reactions absorb heat or energy from the surroundings, leading to an increase in the kinetic energy of the reactant molecules. Therefore, the statement that in exothermic reactions, the reactants have more kinetic energy than the products is false.
3) True. The rate-determining step refers to the slowest step in a chemical reaction, which limits the overall rate at which the reaction proceeds. The order of the rate-determining step is determined by the number of molecules or reactants involved in that step.
When only one molecule is involved in the rate-determining step, it is called a first-order reaction. In a first-order reaction, the rate of the reaction is directly proportional to the concentration of the reactant raised to the power of one. The rate equation for a first-order reaction can be written as rate = k[A], where [A] represents the concentration of the reactant.