An atom has 19 protons and 20 neutrons. what is the atomic number with steps
2 answers:
You might be interested in
Answer : The oxidation-reduction reactions are:
I. reaction of a metal with a nonmetal
II. synthesis
III. combustion
Explanation :
Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.
Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.
Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.
I. Reaction of a metal with a nonmetal :
When sodium react with chlorine gas then it react to give sodium chloride.
In this reaction, the oxidation state of sodium changes from (0) to (+1) and shows oxidation and the oxidation state of chlorine changes from (0) to (-1) and shows reduction. So, It is an oxidation-reduction reaction.
II. Synthesis reaction :
A chemical reaction where multiple substances or reactants combine to form a single product.
When hydrogen react with oxygen then it react to give water.
In this reaction, the oxidation state of hydrogen changes from (0) to (+1) and shows oxidation and the oxidation state of oxygen changes from (0) to (-2) and shows reduction. So, It is an oxidation-reduction reaction.
III. Combustion reaction :
A chemical reaction in which a hydrocarbon reaction with the oxygen to give product as carbon dioxide and water.
When methane react with oxygen gas then it react to give carbon dioxide and water.
In this reaction, the carbon of methane gain oxygen and shows oxidation and the oxygen gas gain hydrogen and shows reduction. So, It is an oxidation-reduction reaction.
IV. Precipitation reaction :
It is defined as the reaction in which an insoluble salt formed when two aqueous solutions are combined.
The insoluble salt that settle down in the solution is known an precipitate.
It is a double displacement reaction. So, it is not an oxidation-reduction reaction.
V. Decomposition reaction :
A chemical reaction in which the the larger molecule decomposes to give two or more smaller molecules.
The oxidation state remains same on reactant and product side. So, it is not an oxidation-reduction reaction.
Answer: The reaction is exothermic
The value is negative.
Heat is a product.
Explanation:
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and for the reaction comes out to be negative.
The substances which are written on the left side of the arrow are reactants and the substances which are written on the right side of the arrow are products. Thus heat is a product.
<u>Answer:</u> The final temperature of water is 32.3°C
<u>Explanation:</u>
When two solutions are mixed, the amount of heat released by solution 1 (liquid water) will be equal to the amount of heat absorbed by solution 2 (liquid water)
The equation used to calculate heat released or absorbed follows:
......(1)
where,
q = heat absorbed or released
= mass of solution 1 (liquid water) = 50.0 g
= mass of solution 2 (liquid water) = 29.0 g
= final temperature = ?
= initial temperature of solution 1 = 25°C = [273 + 25] = 298 K
= initial temperature of solution 2 = 45°C = [273 + 45] = 318 K
c = specific heat of water= 4.18 J/g.K
Putting values in equation 1, we get:
Converting this into degree Celsius, we use the conversion factor:
Hence, the final temperature of water is 32.3°C