Write the atomic number, atomic mass, number of protons, number of neutrons, and number of electrons for each element.

You decided to prepare a phosphate buffer from solid sodium dihydrogen phosphate (NaH2PO4) and disodium hydrogen phosphate (Na2H

KIM [24]

Answer:

For disodium hydrogen phosphate:

5.32g Na2HPO4

For sodium dihydrogen phosphate:

7.65g Na2HPO4

Explanation:

First, you have to put all the data from the problem that you going to use:

-NaH2PO4 (weak acid)

-Na2HPO4 (a weak base)

-Volume = 1L

-Buffer pH = 7.00

-Concentration of [NaH2PO4 + Na2HPO4] = 0.100 M

What we need to find the pKa of the weak acid, in this case NaH2PO4, for that you need to find the Ka (acid constant) of NaH2PO4, and for this we use the pKa of the phosphoric acid as follow:

H3PO4 = H2PO4 + H+ pKa1 = 2.14

H2PO4 = HPO4 + H+ pKa2 = 6.86

HPO4 = PO4 + H+ pKa3 = 12.4

So, for the preparation of buffer, you need to use the pKa that is near to the value of the pH that you want, so the choice will be:

pKa2= 6.86

Now we going to use the Henderson Hasselbalch equation for the pH of a buffer solution:

pH = pKa2 + log [(NaH2PO4)/(Na2HPO4)]

The solution of the problem is attached to this answer.

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7 0

3 years ago

Fill in the coefficients that will balance the following reaction:

vfiekz [6]

6NaC₂H₃O₂ + Fe₂O₃ → 2Fe(C₂H₃O₂)₃ + 3Na₂O

Explanation:

Given equation;

NaC₂H₃O₂ + Fe₂O₃ → Fe(C₂H₃O₂)₃ + Na₂O

To find the coefficient that will balance this we equation, let us set up simple mathematical algebraic expressions that we can readily solve.

Let us have at the back of our mind that, in every chemical reaction, the number of atom is usually conserved.

aNaC₂H₃O₂ + bFe₂O₃ → cFe(C₂H₃O₂)₃ + dNa₂O

a, b, c and d are the coefficients that will balance the equation.

conserving Na; a = 2d

C: 2a = 6c

H: 3a = 9c

O; 2a + 3b = 6c + d

Fe: 2b = c

let a = 1

solving:

2a = 6c

2(1) = 6c

c = $\frac{2}{6} = \frac{1}{3}$

2b = c

b = $\frac{1}{2} x \frac{1}{3}$ = $\frac{1}{6}$

d = 2a + 3b - 6c = 2(1 ) + (3 x $\frac{1}{6}$ ) - (6 x $\frac{1}{3}$ ) = $\frac{1}{2}$

Now multiply through by 6

a = 6, b = 1, c = 2 and d = 3

6NaC₂H₃O₂ + Fe₂O₃ → 2Fe(C₂H₃O₂)₃ + 3Na₂O

learn more:

Balanced equation brainly.com/question/9325293

#learnwithBrainly

6 0

2 years ago

The basic structure of an amino acid contains the amine group, NH2, and a carboxylic acid group separated by one or more carbon

OLEGan [10]

The answer would be True

3 0

3 years ago

Arrange the steps typically followed in the data preparation process in the order of occurrence. (Place the first step at the to

Pavel [41]

Data validation → editing data → entry data → tabulation

This enables better integration, consumption and analysis of larger datasets using advanced business intelligence with analytics solutions.

<h3>What is data preparation ?</h3>

Data collection, combination, structure, and organisation are all steps in the process of preparing data for use in business intelligence (BI), analytics, and data visualisation applications.

Data prep is a common colloquial term for data preparation. It is also referred to as "data wrangling," while other professionals use that phrase more specifically to mean "cleaning, structuring, and transforming data." This usage distinguishes data wrangling from the data pretreatment stage.

Learn more about Data preparation here:

brainly.com/question/28056387

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3 0

1 year ago

A car travels 66 kilometers in 3 hours. what is its speed

Ne4ueva [31]

Answer:

22 kph

Explanation:

You simply divide the distance and the time. 66/3 = 22.

8 0

3 years ago

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