Answer:
The correct answer is: pH= 4.70
Explanation:
We use the <em>Henderson-Hasselbach equation</em> in order to calculate the pH of a buffer solution:
![pH= pKa + log \frac{ [conjugate base]}{[acid]}](https://tex.z-dn.net/?f=pH%3D%20pKa%20%2B%20log%20%20%20%5Cfrac%7B%20%5Bconjugate%20base%5D%7D%7B%5Bacid%5D%7D)
Given:
pKa= 4.90
[conjugate base]= 4.75 mol
[acid]= 7.50 mol
We calculate pH as follows:
pH = 4.90 + log (4.75 mol/7.50 mol) = 4.90 + (-0.20) = 4.70
Answer:
22×10⁻¹³
Explanation:
Scientific notation:
Scientific notation is the way to express the large value in short form.
The number in scientific notation have two parts.
The digits (decimal point will place after first digit)
× 10 ( the power which put the decimal point where it should be)
for example the number 6324.4 in scientific notation will be written as = 6.3244 × 10³
When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value. Thus, in given value,
(4.1357× 10⁻¹⁵) × (5.4×10²)
22×10⁻¹³
Can you send the attachment please so i can help you
Cl because it gains electron and become negatively charged
The <u>Mole</u> is the SI unit that expresses the amount of substance.
Mole is defined as - The mole is the amount of substance containing the same number of entities as there are in the 12 grams of Carbon - 12.
Mole is denoted by using symbol mol.
Mole = 6.022 x 10²³ elementary entities.
These number of elementary entities in 1 mole is equal to or called as an Avogadro's number. Mole is equal to 6.022 x 10²³ because this number of entity is same as in exactly 12 g of carbon-12.
It is a very important SI unit of measured which is used by the chemists. Moles are used in measuring in small or tiny things such as atoms, molecules and the other tiny particles.
To learn more about the mole concept,
brainly.com/question/28498715
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