Answer:
118
Explanation:
The discovery of the 118 chemical element known to exist us of 2021
Answer:
50000mm u add subtract multiply divide
Explanation:
The postulates of Dalton's theory were:
1) Elements are made of extremely small particles called atoms
2) <span>Atoms of a given element are identical in size, mass, and other properties
</span>3) <span>Atoms cannot be subdivided, created, or destroyed</span>
4) Atoms combine in whole number ratio to form compounds
5) Chemical reactions are the rearrangement of atoms
The third postulate has been disproved by modern science, in which the atom has been split and been subdivided into smaller parts such as the neutron, proton and electron, which are further subdivided into quarks, gluons, and kaons.
The second postulate was also disproved upon the discovery of isotopes.
Letter C on the model titration curve corresponds to the point where pH equals the numerical value of pKa for HPr
<h3>What is a titration curve?</h3>
A titration curve is a graph of the pH of a solution against increasing volumes of an acid or a base that is added to the solution.
The pH of a solution is the negative logarithm to base ten of the hydrogen ion concentration and is a measure of the acidity or alkalinity of the solution.
The pKa is the acid dissociation constant of an acid solution.
In a titration of a strong acid and strong base, the pH at equivalence point is equal to the pKa of the acid.
The equivalence point is the point when equal moles of acids and base has reacted.
In the given titration curve, pH = pKa at point C.
In conclusion, for a titration curve of strong acid and base, at equivalence point, pH is equal to pKa of acid.
Learn more about equivalence point at: brainly.com/question/23502649
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Answer:
156 g
Explanation:
Let's consider the following reaction.
2 NaN₃(s) → 2 Na(s) + 3 N₂
(g)
We can find the moles of N₂ using the ideal gas equation.
P × V = n × R × T
1.50 atm × 60.0 L = n × (0.08206 atm.L/mol.K) × 305 K
n = 3.60 mol
The molar ratio of N₂ to NaN₃ is 3:2. The moles of NaN₃ are:
3.60 mol N₂ × (2 mol NaN₃ / 3 mol N₂) = 2.40 mol NaN₃
The molar mass of NaN₃ is 65.01 g/mol. The mass of NaN₃ is:
2.40 mol × 65.01 g/mol = 156 g