Answer:
a. Determine the materials used to make the pots.
Explanation:
Workers digging a tunnel through a city who find some ancient pots decorated with geometric designs will employ the services of a chemist.
The chemist would help to determine the materials which were used to make the pots . This is usually done by various type of experiments and observations. After the constituent of the pot is gotten then more information would be derived from the possible source and use of the pot
B) Sodium and oxygen
C) carbon and oxygen
D) Carbon and sulfur
Answer:
B) Sodium and oxygen
Explanation:
Ionic bond: This type of bond is formed when there is a complete transfer of electrons from one element to another element. Ionic bond is the bond which is formed between the two oppositely charged ions and are held by the strong electrostatic attraction. This is formed between the atoms which have high differing electronegativities. In this bonding one element is always a metal and another is a non-metal.
Thus,
Out of the options, B involves a metal and a nonmetal which is sodium and oxygen respectively. Thus, they can form a ionic bond on combining.
A) represents 2 metals, C) and D) represents 2 nonmetals and thus, they cannot form an ionic bond.
As reactants form products, the potential energy increases.
Thermal energy is transferred from the product to the reacting substances.
Thermal energy is transferred from the surroundings to the reacting substances.
Answer is: As reactants form products, the potential energy decreases.
There are two types of reaction:
1) Endothermic reaction (chemical reaction that absorbs more energy than it releases).
2) Exothermic reaction (chemical reaction that releases more energy than it absorbs).
For example, balanced chemical reaction:
C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O ΔrH= -1370 kJ/mol.
This reaction is exothermic reaction (heat is released), so products have less potential energy and energy is transerred to surroundings.
Considering the definition of exothermic reaction, as reactants form products, the potential energy decreases (first option).
Energy is the ability to do work or to produce heat.
Chemical reactions involve a rearrangement of atoms between substances with the breaking or formation of chemical bonds. In general, this formation or breaking of chemical bonds is accompanied by changes in the energy of the system.
In exothermic reactions, energy is released when they occur (usually this energy is released in form of heat), so the reaction system temperature increases.
In a chemical reaction, the reactants are the compounds that are transformed and give rise to the products. Reactants and products have stored potential energy. In an exothermic reaction, the reactants have more potential energy compared to the products, so the excess energy is released as heat, thus complying with the law of conservation of energy, which says that energy is not lost. gain or loss, so the energy of the reactants must be equal to that of the products.
In summary, considering the definition of exothermic reaction, as reactants form products, the potential energy decreases (first option).
Learn more about exothermic reactions:
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This reaction occurs more quickly when powdered iron is used instead of a single piece of iron of the same mass because the powdered iron
(1) acts as a better catalyst than the single piece of iron
(2) absorbs less energy than the single piece of iron
(3) has a greater surface area than the single piece of iron
(4) is more metallic than the single piece of iron
Answer: Option (3) is the correct answer.
Explanation:
One of the important factor on which rate of reaction depends is surface area. That is, when a compound is crushed into powdered form then there will be increase in surface area of the compound.
Hence, now more number of particles can interact, therefore, there will be increase in rate of reaction.
Thus, we can conclude that reaction occurs more quickly when powdered iron is used instead of a single piece of iron of the same mass because the powdered iron has a greater surface area than the single piece of iron.
Sample response: Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.
This is late but if anyone needs it here you go.
Answer : 3 substance will have 3 mole ratios to be written for a chemical reaction.
Explanation : The mole ratio can be defined as the ratio between the amounts in moles of any two or more compounds involved in a chemical reaction.
It can be determined by comparing the coefficients the formulas of a balanced chemical equation. It is also known as the molar ratio or mole-to-mole ratio.
Hence, when 3 substances are involved in a chemical reaction 3 mole ratios can be written for it.
the reduced substance is Cl2.