Explanation:
a) Using the provided information about the density of gold, the sample size, thickness, and the following equations and comersion factors, find the area of the gold leaf:

Gold 

First, find the volume of the sample and then find the area of the sample.


b. Using the provided information from part
), the radius of the cylinder, and the following equation for the volume of a cylinder, find the length of the fiber :


Actually mass and weight are two different things but most people did not understand the difference between them. And they are used synonymously on the earth. Mass is the measure of the amount of matter and weight is the measure of how the force of gravity acts on the mass that is Weight = mass x force of gravity. And they are also directly proportional to each other that is also the reason both terms are used synonymously.
Answer : The number of moles of oxygen present in a sample are 11.3 moles.
Explanation :
The given compound is, 
By the stoichiometry we can say that, 1 mole of of
has 4 moles of CO.
Or we can say that, 1 mole of of
has 1 mole of nickel (Ni), 4 moles of carbon (C) and 4 moles of oxygen.
That means,
Number of moles of carbon = Number of moles of oxygen
As we are given that:
Number of moles of carbon = 11.3 moles
So, number of moles of oxygen = number of moles of carbon = 11.3 moles
Therefore, the number of moles of oxygen present in a sample are 11.3 moles.
Answer:
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Explanation:
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<u>1. Dissociation equation</u>
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Assuming 100% dissociation, the equation is:
- Ba(C₂H₃O₂)₂ → Ba²⁺ + 2C₂H₃O₂⁻
↑
acetate ions
<u>2. Molarity</u>
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Calculate the molarity, M, of the solution:
- n = mass in grams / molar mass
- n = 69.g / 255.415g/mol = 0.27015 mol
- M = 0.27015mol / 0.970liter = 0.27850 mol/liter ≈ 0.28M
<u>3. Acetate ions</u>
From the chemical equation, 1 mol of dissolved Ba(C₂H₃O₂)₂ produces 2 acetate ions in solution.
Thus, 0.28 mol/liter × 2 = 0.56 mol/liter = 0.56M ← answer