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3 years ago

How is calculating a weighted average

Chemistry

1 answer:

kirza4 [7]3 years ago

8 0

Answer:

The Key difference between average vs weighted average is that simple average is nothing but simply adding up all the observation values and dividing the same by the total number of observations to calculate the average whereas weighted average is an average where each observation value will have a frequency assigned.

Explanation:

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What are the two species in highest concentration in a 0.1 M solution of lactic acid (CH3CH(OH)C00H), (Ka

rusak2 [61]

Answer:

1.4 × 10^-4.

Explanation:

C3H6O3 + H2O <======> C3H5O3^- + H3O^+ ------------------------------------------(1).

So, from the question above we are given the following parameters or data which is going to help in solving this particular Question/problem;

=>concentration of the solution of lactic acid (CH3CH(OH)C00H) = 0.1 M and pH = 2.44.

Therefore, the concentration of the hydrogen ion[H^+} can be determined from the pH formula given below;

pH = - log { H^+}.

2.44 = - log { H^+}.

Therefore, {H^+} = 0.0036 M.

From the equation (1) given above, we have that the ratio for the equilibrium reaction is 1 : 1 : 1 :1. Therefore, molarity of C3H5O3^- = 0.0036 M and the molarity of C3H6O3 =( 0.1 - 0.0036 M) = 0.0964 M at equilibrium.

Hence, ka = {C3H5O3^-} { H3O^+} /{C3H6O3} = ( 0.0036 M)^2 /(0.0964 M) = 1.4 × 10^-4.

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2 years ago

Earth is unique because it is the _____.

astraxan [27]

Answer:

B. The only planet to support life.

Explanation:

5 0

3 years ago

Read 2 more answers

Choose the molecular compound among the substances listed below.

agasfer [191]

Answer: Among the listed substances $XeCl_{4}$ is the molecular compound.

Explanation:

A chemical compound formed by the chemical combination of two or more non-metals is called a molecular compound or covalent compound.

For example, Xe and Cl are non-metals. The compound formed by them is $XeCl_{4}$ which is a molecular compound.

A molecular compound is formed by sharing of atoms between the combining atoms.

Whereas NaF, $MnCl_{2}$ and CaO are all ionic compounds as they are formed by chemical combination of a metal and a non-metal.

Thus, we can conclude that among the listed substances $XeCl_{4}$ is the molecular compound.

4 0

2 years ago

What is the percent composition of the u.s quarter, which has the mass of 5.670g

Vitek1552 [10]

The percent composition of each element can be calculated as follows:
% composition = (mass of element / total mass) * 100

The total mass of the quarter is given to be 5.670 grams
Mass of Cu = 5.198 grams
Mass of Ni = 0.472 grams

Substitute in the above equation to get the mass percentage of each element as follows:
% of Cu = (5.198/5.670) * 100 = 91.675%
% of Ni = (0.472/5.670) * 100 = 8.325%

6 0

2 years ago

How many molecules are in 85g of silver nitrate?

maksim [4K]

<h3>Answer:</h3>

3.0 × 10²³ molecules AgNO₃

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

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Reading a Periodic Table
Writing Compounds
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

85 g AgNO₃ (silver nitrate)

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

Avogadro's Number

[PT] Molar Mass of Ag - 107.87 g/mol

[PT] Molar Mass of N - 14.01 g/mol

[PT] Molar Mass of O - 16.00 g/mol

Molar Mass of AgNO₃ - 107.87 + 14.01 + 3(16.00) = 169.88 g/mol

<u>Step 3: Convert</u>

Set up: $\displaystyle 85 \ g \ AgNO_3(\frac{1 \ mol \ AgNO_3}{169.88 \ g \ AgNO_3})(\frac{6.022 \cdot 10^{23} \ molecules \ AgNO_3}{1 \ mol \ AgNO_3})$
Multiply/Divide: $\displaystyle 3.01313 \cdot 10^{23} \ molecules \ AgNO_3$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 2 sig figs.</em>

3.01313 × 10²³ molecules AgNO₃ ≈ 3.0 × 10²³ molecules AgNO₃

6 0

2 years ago