Balanced chemical reaction: 2CH₄(g) ⇄ C₂H₂(g) + 3H₂(g).
1) In a chemical reaction, chemical equilibrium is the state in which both reactants (methane CH₄) and products (ethyne C₂H₂ and hydrogen H₂) are present in concentrations which have no further tendency to change with time.
2) At equilibrium, both the forward and reverse reactions are still occurring.
3) Reaction rates of the forward and backward reactions are equal and there are no changes in the concentrations of the reactants and products.
2 is your answer hope you get it right
Answer:
H₂(g) + Cl₂(g) → 2HCl(g) + 185kJ
Explanation:
In a chemical reaction, enthalpy of reaction ΔH is a thermodynamic constant that gives information if the reaction is exothermic (Produce heat if reacts) or endothermic (Consume heat if reacts).
In the reaction:
H₂(g) + Cl₂(g) → 2HCl(g) ΔH = -185kJ
As ΔH <0, the reaction is exothermic, that means, <em>produce heat</em>, writing a balanced thermochemical equation:
<em>H₂(g) + Cl₂(g) → 2HCl(g) + 185kJ</em>
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The enthalpy is as a product beacause an exothermic reaction produces heat.
I hope it helps!
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Answer:
The correct answer is B.
Explanation:
The molecule of water has 2 atoms of hydrogen and 1 atom of oxygen.
The ratio of masses are given as:
This illustrates the law of definite proportions which is also known as law of constant compositions .
The law states that 'the elements combining to form compound always combine in a fixed ratio by their mass.'
Whereas :
Law of multiple proportion states that when two elements combine with each other to form more than one compounds , the mass of one element with respect to the fixed mass of another element are in ratio of small whole numbers.
Law of conservation of mass states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
In a balanced chemical reaction ,total mass on the reactant side must be equal to the total mass on the product side.
Law of conservation of energy states that energy can neither be created nor be destroyed but it can only be transformed from one form to another form.
This lesson is the first in a three-part series that addresses a concept that is central to the understanding of the water cycle—that water is able to take many forms but is still water. This series of lessons is designed to prepare students to understand that most substances may exist as solids, liquids, or gases depending on the temperature, pressure, and nature of that substance. This knowledge is critical to understanding that water in our world is constantly cycling as a solid, liquid, or gas.
In these lessons, students will observe, measure, and describe water as it changes state. It is important to note that students at this level "...should become familiar with the freezing of water and melting of ice (with no change in weight), the disappearance of wetness into the air, and the appearance of water on cold surfaces. Evaporation and condensation will mean nothing different from disappearance and appearance, perhaps for several years, until students begin to understand that the evaporated water is still present in the form of invisibly small molecules." (Benchmarks for Science Literacy<span>, </span>pp. 66-67.)
In this lesson, students explore how water can change from a solid to a liquid and then back again.
<span>In </span>Water 2: Disappearing Water, students will focus on the concept that water can go back and forth from one form to another and the amount of water will remain the same.
Water 3: Melting and Freezing<span> allows students to investigate what happens to the amount of different substances as they change from a solid to a liquid or a liquid to a solid.</span>
