25.71 × 10²³ molecules are there in 4.27 mol of tungsten (VI) oxide, .
To find the Number of molecules of substance multiply the number of moles of given substance by Avogadro number
Number of molecules = Number of moles × Avogadro's Number
Avogadro's number is the number of particles in one mole of substance. 6.023 × 10²³ is known as Avogadro's constant / Avogadro's number.
Avogadro's number = 6.023 × 10²³
Now,
Number of molecules in 4.27 moles of
= Number of moles of × Avogadro's Number
= 4.27 × 6.023 × 10²³
= 25.71 × 10²³ molecules
Thus, we can say that 25.71 × 10²³ molecules are there in 4.27 moles of tungsten (VI) oxide, .
Learn more about the Avogadro's Number here: brainly.com/question/859564
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Answer:
Explanation:
Answer:
Reactants
Explanation:
Answer:
Explanation:
Hello,
In this case, considering the required product which is dinitrogen tetroxide whose molecular formula is N₂O₄, by considering its formation reaction which is starting by both gaseous nitrogen and oxygen as shown below:
Nevertheless, it should be balance since four oxygen atoms are present at the right side, thus, we obtain:
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i. Accuracy
ii. Precision
b. A known amount of analyte is added to an aliquot of the sample and analyzed with sample.
i. Accuracy
ii. Precision
c. Aliquots from a blood sample are sent to three separate laboratories for analysis using the same method.
i. Accuracy
ii. Precision
d. Identical standard are analyzed by two different methods.
i. Accuracy
ii. Precision
Answer:
a) Precision
b) Accuracy
c) Accuracy and precision
d) Accuracy
Explanation:
When an experiment is done more than once to determine if the results are statistically ok, two forms of the validations are possible the accuracy and precision. When the values of the various experiments are close to the known value, then they are accurate. When the values are close to each other they are precise. So, sometimes the results are precise but are not accurate, and vice-versa.
a) Here, the person wants to find if the 5 aliquots will have close results, so, he or she is looking for precision.
b) Here the amount of analyte is already known, and the person wants to identify if the value will be the same when analyzed together with another sample, thus he or she is looking for accuracy.
c) Here the three results will be compared with each other (precision) and with the standard value of the method (accuracy).
d) The methods will be tested, and the values will be compared with the standard known value, so the person is looking for accuracy.
Answer:
An Exothermic Reaction , gives off more heat, and a little energy to its surroundings.
this can helps us figure out that the answer is , C, More heat is given off into its products.
Explanation:
Answer: pH = 1.19
Explanation:
The formula for Ka is: Ka = [H+][A-]/[HA]
where: [H+] = concentration of H+ ions
[A-] = concentration of conjugate base ions
[HA] = concentration of undissociated acid molecules
Equation of reaction: Cl₂CHCOOH ---> H+ + Cl₂CHCOO-
From the equation above, dichloroacetic acid dissociates one H+ ion for every Cl₂CHCOO- ion,
so [H+] = [Cl₂CHCOO-].
Let x represent the concentration of H+ that dissociates from HA, then [HA] = C - x where C is the initial concentration.
Substituting these values into the Ka equation:
Ka = x · x / (C -x)
Ka = x²/(C - x)
(C - x)Ka = x²
x² = CKa - Kax
x² + Kax - CKa = 0
Solve for x using the quadratic formula:
x = [-b ± √(b² - 4ac)]/2a
Note: There are two solutions for x. However only the positive value of x is used since x represents a concentration of ions in solution, and so cannot be negative.
x = [-Ka + √(Ka² + 4CKa)]/2
Substitute the values for Ka and C in the equation above:
Ka = 5.0 x 10^-2
C = 0.15 M
x = {-5.0 x 10^-2 + √[(5.0. x 10^-2)² + 4(0.15)(5.0 x 10^-2)]}/2
x = (-5.0 x 10^-2 + 1.80 x 10^-1)/2
x = 0.13/2
x = 6.50 x 10^-2
To find pH, we use the formula;
pH = -log[H+]
pH = -log(x)
pH = -log(6.50 x 10^-2)
pH = -(-1.19)
pH = 1.19
Answer:
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