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Un tecnico di laboratorio deve preparare una soluzione di carbonato di sodio decaidrato, Na2CO3⋅ 10 H2O per eseguire alcune anal

fiasKO [112]

Answer:

1. 3.70 g Na₂CO₃·10H₂O

2. 50.0 mL of the first solution

Explanation:

1. Prepare the solution

(a) Calculate the molar mass of Na₂CO₃·10H₂O

$\begin{array}{rrr}\textbf{Atoms} &\textbf{M}_{\textbf{r}} & \textbf{Mass/u}\\\text{2Na} & 2\times22.99 & 45.98\\\text{1C} & 1\times 12.01 & 12.01\\\text{13O}&13 \times16.00 & 208.00\\\text{20H}&20 \times 1.008 & 20.16\\&\text{TOTAL =} & \mathbf{286.15}\\\end{array}$

The molar mass of Na₂CO₃·10H₂O is 286.15 g/mol.

(b) Calculate the moles of Na₂CO₃·10H₂O

$\text{Moles of Na$_{2}$CO$_{3}\cdot$10H$_{2}$O}\\= \text{0.250 L solution} \times \dfrac{\text{0.0500 mol Na$_{2}$CO$_{3}\cdot$10H$_{2}$O}}{\text{1 L solution}}\\\\= \text{0.0125 mol Na$_{2}$CO$_{3}\cdot$10H$_{2}$O}$

(c) Calculate the mass of Na₂CO₃·10H₂O

$\text{Mass of Na$_{2}$CO$_{3}\cdot$10H$_{2}$O }\\= \text{0.012 50 mol Na$_{2}$CO$_{3}\cdot$10H$_{2}$O } \times \dfrac{\text{296.15 g Na$_{2}$CO$_{3}\cdot$10H$_{2}$O}}{\text{1 mol Na$_{2}$CO$_{3}\cdot$10H$_{2}$O}}\\\\= \text{3.70 g Na$_{2}$CO$_{3}\cdot$10H$_{2}$O}\\\text{You need $\large \boxed{\textbf{3.70 g}}$ of Na$_{2}$CO$_{3}\cdot$10H$_{2}$O}$

2. Dilute the solution

We can use the dilution formula to calculate the volume needed.

V₁c₁ = V₂c₂

Data:

V₁ = ?; c₁ = 0.0500 mol·L⁻¹

V₂ = 100 mL; c₂ = 0.0250 mol·L⁻¹

Calculation:

$\begin{array}{rcl}V_{1}c_{1} & = & V_{2}c_{2}\\V_{1}\times \text{0.0500 mol/L} & = & \text{100 mL} \times\text{0.0250 mol/L}\\0.0500V_{1}& = & \text{2.500 mL}\\V_{1}&=& \dfrac{\text{2.500 mL}}{0.0500}\\\\& = & \text{50.0 mL}\\\end{array}\\\text{You need $\large \boxed{\textbf{50.0 mL}}$ of the concentrated solution.}$

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2 years ago

What is a common misconception about not following food regulations?

Dima020 [189]

Explanation:

Most Americans have encountered some bacteria at some point in their lives, whether it was acquired from restaurant food or a grocery store, which caused them to claim they later had food poisoning. There are multiple nasty bacteria that can cause this, and there are many misconceptions about how they end up in our food, and what the best ways to avoid them are. To be forewarned is to be forearmed, so here are several misconceptions about food safety and the practices involved that can leave us satisfied, or ruin our day with stomach churning nastiness.

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Describe the type of force which exists between particles in an Ideal gas. Explain why this type of force exists between the par

aksik [14]

The Intermolecular force is a type of force which exists between particles in an Ideal gas.

<h3>What type of force which exists between particles in an Ideal gas?</h3>

Intermolecular forces are considered weaker attractions that hold molecules in gas close together. This force of attraction is present between molecules or particles.

So we can conclude that the Intermolecular force is a type of force which exists between particles in an Ideal gas.

Learn more about attraction here: brainly.com/question/1308963

#SPJ1

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1 year ago

Which of the following is not radiation ? A. baking in a metal pan in the oven , B. heat from a fire , C. microwaving food , or

IRISSAK [1]

Answer:

C.

Explanation:

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The energy source used in nuclear power plants today is

Klio2033 [76]

Answer:

B I have taken the quiz already 90%

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How many of u usses. zoom and wanna j oin it​

How many of u usses. zoom and wanna j oin it