In any chemical reaction, the quantities that are preserved are what?
A. the number of moles and the volumes
B. the number of molecules and the volumes
C. mass and number of atoms
D. mass and moles
Look at C as a possible answer.
what's the answer
The quantities that are preserved in any chemical reaction are the mass and number of atoms. Therefore, the correct answer is option C: mass and number of atoms.
The quantities that are preserved in any chemical reaction are mass and number of atoms. This is known as the law of conservation of mass. According to this law, in a chemical reaction, the total mass of the reactants will be equal to the total mass of the products.
To determine the correct answer, we need to understand the concept of balanced chemical equations. When writing a balanced chemical equation, we use coefficients in front of each molecule or formula to indicate the number of molecules or atoms involved in the reaction. For example, in the equation 2H2 + O2 -> 2H2O, the coefficient 2 in front of H2 indicates that two molecules of H2 are required, while the coefficient 2 in front of H2O indicates that two molecules of H2O are formed.
By examining the balanced equation, it becomes clear that the number of moles and volumes (option A) is not preserved because the coefficients in front of the molecules may not be equal to each other. Similarly, the number of molecules and volumes (option B) is not necessarily preserved because the coefficients can vary.
However, the law of conservation of mass tells us that the total mass of all the reactant atoms will be equal to the total mass of all the product atoms. Therefore, the correct answer is C: mass and number of atoms.