Answer:
a. Raise the pH slightly
Explanation:
We know that
Pka of HNO2/KNO2 =3.39
Moles of HNO2 in the buffer=0.247 mol/L×1L=0.247 moles
Moles of NO2-=0.329mol/L×1L=0.329 moles
If 0.271 moles of Ca(OH)2 is added it will neutralise 0.136 moles of acid ,HNO2,remaining HNO2=0.247-0.136=0.111 moles
Moles of NO2- will increase as 0.0333 moles Ca(NO)2 will be formed =0.0333+0.036=0.0693 moles
pH=pka+log [base]/[acid] {henderson -hasselbach equation}
=3.39+log (0.0693/0.0317)=3.39+0.34=3.73
pH=3.73
The element is silicon (Si). It forms minerals like quartz and rocks such as granite.
Hot and cold water can be mixed together to make warm water is the correct statement that shows role of chemistry.
<h3>
What demonstrates the role of chemistry?</h3>
Hot and cold water can be mixed together to make warm water is the statement that demonstrates the role of chemistry in getting ready for school in the morning because it describes the features of warm water. It also shows the method of getting warm water from mixing of hot and cold water.
So we can conclude that Hot and cold water can be mixed together to make warm water is the correct statement that shows role of chemistry.
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Answer:
X = 2
Explanation:
As you know, the rate of a first-order reaction depends linearly on the concentration of a single reactant. The rate of a first-order reaction that takes the form
<u>True,</u> A mole of one substance has the same number of atoms as a mole of any other substance.
<h3>
What is a mole?</h3>
Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles.
The mole designates an extremely large number of units, 6.02214076 × 
. The General Conference on Weights and Measures defined the mole as this number for the International System of Units (SI) effective from May 20, 2019. The mole was previously defined as the number of atoms determined experimentally to be found in 12 grams of carbon-12.
The number of units in a mole also bears the name Avogadro’s number, or Avogadro’s constant, in honour of the Italian physicist Amedeo Avogadro (1776–1856). Avogadro proposed that equal volumes of gases under the same conditions contain the same number of molecules, a hypothesis that proved useful in determining atomic and molecular weights and which led to the concept of the mole.
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