Answer:
The answer I would go with is A formation of a new substance.
Explanation:
This is because physical change includes changes of state. Some could be changing from a liquid to gas or solid to gas. B is not even an answer that should be considered because it doesn't fit into the category. C and D represents some of the examples of the process of physical change. Like boiling, bubbling, melting, or freezing. So the best would be A.
Answer:
Multiply the element's atomic mass by the number of atoms of that element in the compound. This will give you the relative amount that each element contributes to the compound. For hydrogen chloride, HCl, the molar mass of each element is 1.007 grams per mole for hydrogen and 35.453 grams per mole for chlorine.
Answer: Equilibrium
Explanation:
The reactions which do not go on completion and in which the reactant forms product and the products goes back to the reactants simultaneously are known as equilibrium reactions.
For a chemical equilibrium reaction, equilibrium state is achieved when the rate of forward reaction becomes equals to rate of the backward reaction which means the products are being made as quickly as reactants
Equilibrium state is the state when reactants and products are present but the concentrations does not change with time.
Answer:
n = 0.207 mole
Explanation:
We have,
P = 1 atm
V = 5 liter
R = 0.0821 L.atm/mol.K
T = 293 K
We need to find the value of n. The relation is as follows :
PV = nRT
Solving for n,

So, the value of n is 0.207 mol.