Answer:
Model
Explanation:
A model of anything is something you make to represent it in it's physical world form
Answer:
E
Explanation:
A catalyst is a substance which alters the rate of a chemical reaction. We check for the correctness of each of the options as follows:
A. Is wrong.
A catalyst can increase the rate of the forward and backward reaction
B. Is wrong
A catalyst does not slow the reverse reaction only. This particular case is the case of a negative catalyst
C is wrong
A catalyst has no effect on the equilibrium nor the equilibrium constant
D is wrong
Catalyst has no effect on equilibrium value
E is correct
Although Catalysts has no effect on equilibrium or its constant value, it can increase the the rate at which equilibrium is achieved by speeding up the reaction through bringing down the activation energy
1) Chemical reaction
HCl + NaOH ---> NaCl + H2O
25.0 ml
0.150 M 0.250M
2) 50% completion => 0.025 l * 0.150 M * (1/2) = 0.001875 mol HCl consumed and 0.001875 mol HCl in solution
0.001875 mol HCl => 0.001875 mol H(+)
Volume = Volume of HCl solution + Volumen of NaOH solution added
Volume of HCl solution = 0.0250 l
Volume of NaOH = n / M = 0.001875 mol / 0.250M = 0.0075 l
Total volume = 0.0250 l + 0.0075 l = 0.0325 l
[H+] = 0.001875 mol / 0.0325 l = 0.05769 M
pH = - log [H+] = - log (0.05769) = 1.23
Answer: 1.23
3) Equivalence point
0.02500 l * 0.150 M = 0.250M * V
=> V = 0.02500 * 0.150 / 0.250 = 0.015 l
4) 1.00 ml NaOH added beyond the equivalence point
1.00 ml * 1 l / 1000 ml * 0.250 M = 0.00025 mol NaOH in excess
0.00025 mol NaOH = 0.00025 mol OH-
Volume of the solution = 0.02500 l + 0.015 l + 1.00/1000 l = 0.041 l
[OH-] = 0.00025 mol / 0.041 l = 0.00610 M
pOH = - log (0.00610) = 2.21
pH + pOH = 14 => pH = 14 - pOH = 14 - 2.21 = 11.76
Answer: 11.76
Answer:
1.- Chemical change
2.- Because the atoms in the image are tranformed into a new molecule
3.- Yes, it does
4.- Due to the amount of atoms are the same both in products and reagents
Explanation:
Answer:
The answer is A. solvent, solute, solution.
Explanation:
