Explanation:
The law of conservation of mass states that the total mass of the products is equal to the total of the reactants.
A chemical change occurs because of a chemical reaction.
In a chemical reaction, the reactants are the starting substances and the products is the finishing substances. The amount of each type of atoms to start with and end with are also equal.
No matter disappears after a chemical reaction.
Answer:
The amount of matter in the new substances is the same as the original.
This is known as the law of conservation of mass.
The answer is B because isotopes have the same number of protons and neutrons.
Answer:
0.4 M
Explanation:
Equilibrium occurs when the velocity of the formation of the products is equal to the velocity of the formation of the reactants. It can be described by the equilibrium constant, which is the multiplication of the concentration of the products elevated by their coefficients divided by the multiplication of the concentration of the reactants elevated by their coefficients. So, let's do an equilibrium chart for the reaction.
Because there's no O₂ in the beginning, the NO will decompose:
N₂(g) + O₂(g) ⇄ 2NO(g)
0.30 0 0.70 Initial
+x +x -2x Reacts (the stoichiometry is 1:1:2)
0.30+x x 0.70-2x Equilibrium
The equilibrium concentrations are the number of moles divided by the volume (0.250 L):
[N₂] = (0.30 + x)/0.250
[O₂] = x/0.25
[NO] = (0.70 - 2x)/0.250
K = [NO]²/([N₂]*[O₂])
K = ![\frac{(\frac{0.70 -2x}{0.250})^2 }{\frac{0.30+x}{0.250}*\frac{x}{0.250} }](https://tex.z-dn.net/?f=%5Cfrac%7B%28%5Cfrac%7B0.70%20-2x%7D%7B0.250%7D%29%5E2%20%7D%7B%5Cfrac%7B0.30%2Bx%7D%7B0.250%7D%2A%5Cfrac%7Bx%7D%7B0.250%7D%20%7D)
7.70 = (0.70-2x)²/[(0.30+x)*x]
7.70 = (0.49 - 2.80x + 4x²)/(0.30x + x²)
4x² - 2.80x + 0.49 = 2.31x + 7.70x²
3.7x² + 5.11x - 0.49 = 0
Solving in a graphical calculator (or by Bhaskara's equation), x>0 and x<0.70
x = 0.09 mol
Thus,
[O₂] = 0.09/0.250 = 0.36 M ≅ 0.4 M