Answer:
Explanation:
a) In an exothermic reaction, the energy transferred to the surroundings from forming new bonds is ___more____ than the energy needed to break existing bonds.
b) In an endothermic reaction, the energy transferred to the surroundings from forming new bonds is ___less____ than the energy needed to break existing bonds.
c) The energy change of an exothermic reaction has a _____negative_______ sign.
d) The energy change of an endothermic reaction has a ____positive________ sign.
The energy changes occur during the bonds formation and bonds breaking.
There are two types of reaction endothermic and exothermic reaction.
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Answer:
How many moles of oxygen are in 2.71 x 1025 molecules of carbon dioxide (CO2)? 90 moles. How many moles are there in 125 grams of carbon? 10.42 moles of carbon.
Explanation:
"<span>It will sink because soap disrupts the intermolecular forces of water" is the statement among the choices given in the question that describes what will likely happen to the twig </span><span>if a drop of dishwashing detergent is added near it. The correct option among all the options that are given in the question is the third option. </span>
Answer: 15.2 grams
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
where,
n= moles of solute
= volume of solution in ml
moles of solute (nickel (II) chloride hexahydrate ) =
Putting the values , we get
Thus 15.2 grams of nickel (II) chloride hexahydrate are required to prepare 250. mL of aqueous solution whose concentration is 0.255 M.