(a) The temperature goes up by 3⁰C.
(b) There is increase in temperature, so the reaction is exothermic.
(c) Examples of exothermic reaction include, rusting of Iron, burning of coal, reaction of strong acid and water.
(d) Examples of endothermic reaction include, melting solid salts and evaporating liquid water.
<h3>
What is exothermic reaction?</h3>
Exothermic reaction is a type of chemical reaction in which energy is transferred to or from the surroundings.
Examples of exothermic reactions include the following;
- Rusting of Iron
- Burning of Coal
- Reaction of Strong Acid and Water
- Water and Calcium Chloride
<h3>What is endothermic reaction?</h3>
Endothermic reaction is a type of chemical reaction in which energy is absorbed from the surroundings.
Examples of endothermic reactions include the following;
- Melting solid salts.
- Evaporating liquid water, etc
<h3>Change in temperature</h3>
From the increase in temperature from 15⁰C to 23⁰C, we can conclude that the temperature goes up by 3⁰C.
20⁰C - 17⁰C = 23⁰ - 20⁰C = 3⁰C.
Since there is increase in temperature, the reaction is exothermic.
Learn more about exothermic reaction here: brainly.com/question/2924714
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Hello, this question is incomplete. The complete question would be:
"Write the balanced chemical equation for the following reaction.
Solid iron(III) oxide reacts with hydrogen gas to form solid iron and liquid water"
Answer:
Fe2O3 + 3 H2 = 2 Fe + 3 H2O
Explanation:
In a chemical reaction, the structure of atoms as chemical elements is unchanged. Atoms in one element do not become atoms in another element. There is also no loss or creation of new atoms. The number of atoms of the reagents must be equal to the number of atoms of the products. When this happens, we say that the chemical equation is balanced.
For this reason, we can state that the balanced chemical reaction where solid iron (III) oxide reacts with hydrogen gas to form solid iron and liquid water would be:
<em>Fe2O3 + 3 H2 = 2 Fe + 3 H2O
</em>
Given that the volume of the pure water is 480 mL and the mole of HCl added to the water is 2×10¯² mole. Therefore, the Initial and final pH of the water are:
1. The initial pH of the pure water is 7
2. The final pH of the water is 1.38
<h3>What is pH ? </h3>
This is simply a measure of the acidity / alkalinity of a solution.
The pH measures the hydrogen ion concentration while the pOH measures the hydroxide ion concentration
<h3>pH scale </h3>
The pH scale is a scale that gives an understanding of the variation of the acidity / alkalinity of a solution.
The scale ranges from 0 to 14 indicating:
- 0 to 6 indicates acid
- 7 indicates neutral (pure water)
- 8 to 14 indicate basic
<h3>How to determine the molarity </h3>
- Volume = 480 mL = 480 / 1000 = 0.48 L
- Mole of HCl = 2×10¯² mole
Molarity = mole / Volume
Molarity = 2×10¯² / 0.48
Molarity = 4.17×10¯² M
<h3>Dissociation equation </h3>
HCl(aq) —> H⁺(aq) + Cl¯(aq)
From the balanced equation above,
1 mole of HCl contains 1 mole of H⁺
Therefore,
4.17×10¯² M HCl will also contain 4.17×10¯² M H⁺
<h3>How to determine the pH </h3>
- Hydrogen ion concentration [H⁺] = 4.17×10¯² M
- pH =?
pH = –Log H⁺
pH = –Log 4.17×10¯²
pH = 1.38
Learn more about pH:
brainly.com/question/3709867
Answer:
Gene - determines the trait (phenotype)
Explanation:
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