Answer:
56.9 mmoles of acetate are required in this buffer
Explanation:
To solve this, we can think in the Henderson Hasselbach equation:
pH = pKa + log ([CH₃COO⁻] / [CH₃COOH])
To make the buffer we know:
CH₃COOH + H₂O ⇄ CH₃COO⁻ + H₃O⁺ Ka
We know that Ka from acetic acid is: 1.8×10⁻⁵
pKa = - log Ka
pKa = 4.74
We replace data:
5.5 = 4.74 + log ([acetate] / 10 mmol)
5.5 - 4.74 = log ([acetate] / 10 mmol)
0.755 = log ([acetate] / 10 mmol)
10⁰'⁷⁵⁵ = ([acetate] / 10 mmol)
5.69 = ([acetate] / 10 mmol)
5.69 . 10 = [acetate] → 56.9 mmoles
Answer:
Zirconium
Explanation:
Given that,
Mass number = 92
No of neutrons = 52
Mass number is the sum of the number of protons and neutrons. We can find the number of protons.
92 = 52 + P
P = 40
Atomic number is equal to the number of protons. It means that the atomic no of the element is 40. The element is Zirconium whose atomic number is 40 and mass number is 92.
MgCl₂ & PbSO₄ is the correct product for the given double replacement reaction.
<h3>What is double displacement reaction?</h3>
In the double displacement reaction displacement of two substrate will take place among two reactants and formation of products takes place.
In the question, PbCl₂ reacts with MgSO₄ and displacement between the cations takes place and formation of MgCl₂ and insoluble precipitate PbSO₄ is formed.
Given reaction is represented as:
PbCl₂ + MgSO₄ → MgCl₂ + PbSO₄
According to the activity series, reactivity of Magnesium is more as compared to the lead atom. So lead is displaced by the magnesium atom and form the above given products.
Hence, option (3) is correct i.e. MgCl₂ & PbSO₄.
To know more about double displacement reaction, visit the below link:
brainly.com/question/26413416
When you inhale, air passes through the nasal cavity. There, mucus and hairs clean the air from most foreign particles before entering the body. Then, the air passes from the nasal cavity to the pharynx. After the pharynx, it passes through the larynx reaching the trachea. After passing through the trachea, the air reaches the bronchi, and after the bronchi, the bronchioles that branch off the bronchi. From the bronchioles, the air reaches the alveoli that is when gas exchange happens. O2 enters and CO2 leaves.
