Answer:
pKb = 10.96
Explanation:
Tartaric acid is a dyprotic acid. It reacts to water like this:
H₂Tart + H₂O ⇄ H₃O⁺ + HTart⁻ Ka1
HTart⁻ + H₂O ⇄ H₃O⁺ + Tart⁻² Ka2
When we anaylse the base, we have
Tart⁻² + H₂O ⇄ OH⁻ + HTart⁻ Kb1
HTart⁻ + H₂O ⇄ OH⁻ + H₂Tart Kb2
Remember that Ka1 . Kb2 = Kw, plus pKa1 + pKb2 = 14
Kb2 = Kw / Ka1 → 1×10⁻¹⁴ / 9.20×10⁻⁴ = 1.08×10⁻¹¹
so pKb = - log Kb2 → - log 1.08×10⁻¹¹ = 10.96
Answer:
Alkali metals
Explanation:
The alkali metals are a group of metallic elements which are present in the first group of the periodic table. In other words, they are present in group 1 of the periodic table. These elements have one electron in their valence shell, the reason why they are placed in group 1.
They ionize by losing one electron to achieve the configuration of the nearest Noble gas or inert gas. Because they need to offset only one electron in their outermost shell, they are very chemically reactive and hence rarely occur in the free state.
Examples of elements in this group include lithium, potassium and sodium. They each have one electron only in their outermost shells.
1) Zn + 2 HCl = ZnCl2 + H2 ( <span>single replacement )
2) </span>2 NaCl + F2 = 2 NaF + Cl2 ( <span>single replacement )
3) </span>2 AlBr3 + 3 K2SO4 = 6 KBr + Al2(SO4)3 ( <span>double replacement )
4) </span>2 K + MgBr2 = 2 KBr + Mg ( <span>single replacement )
Answer 3
hope this helps!</span>
Which of these measurements is expressed as three significant figures?
C. 4.20 g
Answer: First of all planning is done to set the goals to how to test the target. then scanning is done. after that target is uncovered to see how the target exploits by the use of web application attacks. then analysis is done an tests of the penetration tests are compiled.
Explanation:
