The answer is (2) Copper. Because copper is consist of atom. If it is decomposed, the atom will be changed. While chemical change is just the break down and form of chemical bonds between atoms.
An iron atom has a charge of zero. It's charge increases to 2+. Due to the increase in oxidation state, the atom is said to be oxidised. Oxidation occurs when an atom loses electrons.
Hence, the answer is (a).
Because you are never 100% precise during the work, so it's best and most accurate answer is always the average of more trials. basically the more you do, the more accurate the answer shall be
Answer:
0.13 M ( 2 s.f)
Explanation:
2Cl2O5 (g)-->2Cl2(g) +5O2 (g)
rate= (17.4 M -1 .s -1 ) [Cl2O5]2
From the rte above, we can tell that our rate constant (k) = 17.4 M -1 .s -1
The units of k tells us this is a second order reaction.
Initial Concentration [A]o = 1.46M
Final Concentration [A] = ?
Time = 0.400s
The integrated rate law for second order reactions is given as;
1 / [A] = (1 / [A]o) + kt
1 / [A] = [ (1/ 1.46) + (17.4 * 0.4) ]
1 / [A] = 0.6849 + 6.96
1 / [A] = 7.6496
[A] = 1 / 7.6496
[A] = 0.13073 M ≈ 0.13 M ( 2 s.f)
Answer:
7.41 × 10⁻⁵
Explanation:
Let's consider the basic dissociation reaction of trimethylamine (CH₃)N).
(CH₃)N + H₂O = (CH₃)NH⁺ + OH⁻
According to Brönsted-Lowry, in this reaction (CH₃)N is a base and (CH₃)NH⁺ is its conjugate acid. The pKb for (CH₃)N is 9.87. We can calculate the pKa of (CH₃)NH⁺ using the following expression.
pKa + pKb = 14
pKa = 14 - pKb = 14 - 9.87 = 4.13
Then, we can calculate the acid dissociation constant for (CH₃)NH⁺ using the following expression.
pKa = -log Ka
Ka = antilog - pKa = antilog -4.13 = 7.41 × 10⁻⁵
