Answer: "The reactants are higher in energy than the products"
Explanation:
The exothermic reactions are characterized by the release of heat to the surroundings. The reactants lose heat that is delivered to the surroundings which implies that the products will be lower in energy than the reactants.
The hills that you can see in a reaction energy diagram are not related with the final change of energy. The hills are an indication of the activation energy needed to start the reaction, but they do not measure the change of energy from the products to the reactants.
The enthalpy that is a state variable that identifies the content of heat. Then the change of enthalpy for the exothermic reactions is negative, meaning that the energy of the products is lower than the energy of the reactants.
Answer:
The ability of the molecule to pack more tightly increases the melting point.
Explanation:
In hydrocarbons of same molecular formula, melting point is determined by:
- weak intermolecular forces
- Molecular symmetry
Higher the intermolecular forces and molecular symmetry, higher will be the melting point.
Intermolecular forces in hydrocarbons decreases with branching. Moreover, branching interfere the tight packing of the molecule in the crystal. Therefore, branched hydrocarbons tend to have lower melting point.
However, in highly branched hydrocarbons molecular symmetry increases which results in tight packing of the molecule in the crystal.
So, highly tight packed molecules tend to have high melting point.
As (CH3)2CHC(CH3)3 is highly branched and has high molecular symmetry, therefore, its melting point is highest among given.
So, among the given, option c is correct.
Answer: Reactants and Products
Explanation:
The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products.
Momentum = Mass x Velocity
80kg Runner: 80 x 2.45 = 196 Kg m/s
65kg Runner: 65 x 3= 195 Kg m/s
The 80kg runner has a greater momentum
