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2 years ago

How many moles are in 3.113 g of Au?Molar mass of Au=197 g/mol

Chemistry

1 answer:

SVEN [57.7K]2 years ago

3 0

<h3>Answer:</h3>

0.0157 g Au

<h3>General Formulas and Concepts:</h3>

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table
Using Dimensional Analysis

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

<h3>Explanation:</h3>

<u>Step 1: Define</u>

3.113 g Au

<u>Step 2: Identify Conversions</u>

Molar Mass of Au - 197.87 g/mol

<u>Step 3: Convert</u>

<u /> $3.113 \ g \ Au(\frac{1 \ mol \ Au}{197.87 \ g \ Au} )$ = 0.015733 g Au

<u>Step 4: Check</u>

<em>We are given 3 sig figs. Follow sig fig rules and round.</em>

0.015733 g Au ≈ 0.0157 g Au

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Answer:

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2 years ago

Chloroform is an excellent solvent for extracting caffeine from water. The distribution coefficient, KD, (Cchloroform/Cwater) fo

Art [367]

The relative volumes of chloroform and water that should be used is 9:10

Concentration of solution in chloroform = $90$ ( moles of chloroform )

Concentration of solution in water = $10$ ( moles of water )

Dissociation constant at $25^oC$ ; $K_D = 10$

$K_D =$ Concentration of solution in chloroform / Concentration of solution in water

Meaning;

$K_D = \frac{\frac{mole\ of\ chloroform}{volume\ of\ chloroform} }{\frac{mole\ of\ water}{volume\ of\ water} }$

Since $90$ mole is present in chloroform and $10$ mole is present in water, Total mole of Caffeine present is $100$

Now, we substitute our given values into the equation

$10 = \frac{\frac{90}{volume\ of\ chloroform} }{\frac{10}{volume\ of\ water} }\\\\10 *\frac{10}{volume\ of\ water} = \frac{90}{volume\ of\ chloroform} \\\\\frac{100}{volume\ of\ water} = \frac{90}{volume\ of\ chloroform}\\\\\frac{volume\ of\ chloroform}{volume\ of\ water} = \frac{90}{100}\\\\ \frac{volume\ of\ chloroform}{volume\ of\ water} = \frac{9}{10}\\\\ \frac{volume\ of\ chloroform}{volume\ of\ water} = 9:10$