Answer : The correct option is, (A) the copper must have combined with another substance.
Explanation :
According to the question, when a sample of copper powder is heated in an evaporating dish by using Bunsen burner then the mass of the powder in the evaporating dish increases after heating that means the copper powder will be combined with the another substance.
If the mass of powder in the evaporating dish is decreases after the heating then the copper powder must have lost some matter.
The given option C and D are wrong statements because the hot copper is less dense than the cold copper and as we know that the density is directly proportional to the mass of a substance that means the hot copper weighs less than cold copper.
Hence, the correct option is, (A) the copper must have combined with another substance.
Answer:
The pH of an aqueous solution is the measure of how acidic or basic it is. The pH of an aqueous solution can be determined and calculated by using the concentration of hydronium ion concentration in the solution.
Explanation:
The law of conservation of matter basically states that matter can’t be created or destroyed, only changed in form, so you can rule out any option that mentions destroying or creating matter. That leaves only option A. Atoms cannot be created or destroyed by chemical reactions.
Answer:
1. The oxidation state of all the atoms should change
2. 10
Explanation:
Redox reactions are reactions in which one specie is reduced and another specie is oxidised simultaneously. Such reactions involves the transfer of electrons, that is, one specie loses electrons and the other accepts the lost electrons.
In a redox reaction, there is an increase in oxidation number of an atom that undergoes oxidation and a decrease in oxidation number for atoms that undergoes reduction.
2. There would 10 oxygen on the product side of the reaction.
In balancing chemical equations, the law of conservation of matter is usually followed. The law states that "matter is neither created nor destroyed in the course of a chemical action". This implies that the total mass of the reacting substance is exactly equal to the total mass of the products. This laws simply shows that every atom on the product end must be accounted for on the reactant side.
The equation which shows the combustion of propane would yield carbondioxide and water with the total number of oxygen atoms on the product end being 10.