Answer:
Option d. 7
Explanation:
A mixture of a strong base and a strong acid produce a neutral salt and water.
This is the reaction of neutralization:
HCl + NaOH → NaCl + H₂O
NaCl → Na⁺ + Cl⁻
Sodium chloride is neutral salt which does not give H⁻ neither OH⁻ to medium, that's why pH is neutral.
Both ions are derivated from a strong acid and base so they do not make hydrolisis. They are a conjugate pair of a weak acid and base. The reactions can not occur:
Cl⁻ + H₂O ← OH⁻ + HCl
Na⁺ + H₃O⁺ ← NaOH + H₂O
Answer:
Half-life = 3 minutes
Explanation:
Using the radioactive decay equation we can solve for reaction constant, k. And by using:
K = ln2 / Half-life
We can find half-life of polonium-218
Radioactive decay:
Ln[A] = -kt + ln [A]₀
Where:
[A] could be taken as mass of polonium after t time: 1.0mg
k is Reaction constant, our incognite
t are 12 min
[A]₀ initial amount of polonium-218: 16mg
Ln[A] = -kt + ln [A]₀
Ln[1.0mg] = -k*12min + ln [16mg]
-2.7726 = - k*12min
k = 0.231min⁻¹
Half-life = ln 2 / 0.231min⁻¹
<h3>Half-life = 3 minutes</h3>
D = m / V
0.736 = 225.0 / V
V = 225.0 / 0.736
V = 305.7 cm³
Answer: Another useful feature of the periodic table is that most tables provide all the information you need to balance chemical reactions at a glance. The table tells each element's atomic number and usually its atomic weight. The typical charge of an element is indicated by its group.
Explanation: