Mention the main applications of analytical chemistry in geology.

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.}$

7 0

3 years ago

Given the following equation: 8Fe+S8=8FeS

maxonik [38]

Answer:

a. 2954g of FeS

b. 1143g of FeS

Explanation:

Based on the reaction:

8 Fe + S₈ → 8 FeS

8 moles of Fe reacts with 1 mole of S₈ to produce 8 moles of FeS

a. 4.2mol sulfur produce:

4.2mol S₈ × ( 8 mol FeS / 1 mol S₈) = 33.6mol FeS. As molar mass of FeS is 87.92g/mol, mass is:

33.6mol FeS × ( 87.92g / 1 mol FeS) = 2954g of FeS

b. 13mol Fe produce:

13mol Fe × ( 8 mol FeS / 8 mol Fe) = 13mol FeS. In mass:

13 mol FeS × ( 87.92g / 1 mol FeS) = 1143g of FeS

5 0

3 years ago

Which image shows 2-hexyne?

MaRussiya [10]

Answer: C

Explanation:

A. Shows 3-Hexyne (NOT 2-HEXYNE)

B. Shows 7 carbons (too many) (NOT 2-HEXYNE)

C. Shows a triple bond (yne) and 6 carbons and it's on the second carbon (2-HEXYNE)

D. Shows two substitent on the second carbon but the triple bond is on the 3rd carbon so it's 2,2-dimethyl-3-heptyne (NOT 2-HEXYNE)

4 0

3 years ago

What is the number of moles of solute in a .3 molality solution containing .10 kg of solvent?

denpristay [2]

Concentration can be expressed in different forms: molarity, molality, normality, percentage, part per million and many more. For molality, it is a unit of concentration expressed as moles of solute per kilogram of solvent. Therefore,

0.3 = moles solute/0.10 kg solvent
moles solute = 0.03 moles

4 0

4 years ago

Read 2 more answers

Give an example of how you can conserve energy.

Archy [21]

Ok, my favorite is turning lights off when not in use OR changing out old lightbulbs that are more efficient. :)

5 0

3 years ago