According to one acid-base theory, a water molecule acts as an acid when the water molecule

The forensic technician at a crime scene has just prepared a luminol stock solution by adding 18.0 g of luminol into a total vol

Paladinen [302]

Answer:

1.36M

Explanation:

Luminol is a compound having the molecular formula as C8H7N3O2.

To know the molarity of the stock solution of Luminol, we shall carry out the following:

Step 1:

we shall calculate the number of mole in 18g of luminol. This is shown below:

Molar mass of C8H7N3O2 = (12x8) + (7x1 ) + (14x3) + (16x2)

= 96 + 7 + 42 + 32

= 177g/mol

Mass of C8H7N3O2 = 18g

Number of mole of C8H7N3O2 =..?

Mole = Mass /Molar Mass

Number of mole of C8H7N3O2 = 18/177 = 0.102 mole.

Step 2:

Conversion of 75.0 mL of H2O to Litre (L).

1000mL = 1L

Therefore, 75mL = 75/1000 = 0.075L

Step 3:

Determination of the molarity of the stock solution of Luminol.

Molarity is simply defined as the mole of solute per unit litre of water. Mathematically, it is represented as:

Molarity = mole /Volume

With the above formula, we can obtain the molarity of the stock solution of Luminol as follow:

Mole of C8H7N3O2 = 0.102 mole

Volume of water = 0.075L

Molarity =..?

Molarity = mole /Volume

Molarity = 0.102/0.075

Molarity = 1.36M

Therefore, the molarity of the stock solution of Luminol is 1.36M.

3 0

3 years ago

Gaseous methane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 9.6 g of methane is

lianna [129]

Answer:

21.6 g

Explanation:

The reaction that takes place is:

CH₄ + 2O₂ → CO₂ + 2H₂O

First we convert the given masses of both reactants into moles, using their respective molar masses:

9.6 g CH₄ ÷ 16 g/mol = 0.6 mol CH₄

64.9 g O₂ ÷ 32 g/mol = 2.03 mol O₂

0.6 moles of CH₄ would react completely with (2 * 0.6) 1.2 moles of O₂. As there are more O₂ moles than required, O₂ is the reactant in excess and CH₄ is the limiting reactant.

Now we calculate how many moles of water are produced, using the number of moles of the limiting reactant:

0.6 mol CH₄ * $\frac{2molH_2O}{1molCH_4}$ = 1.2 mol H₂O

Finally we convert 1.2 moles of water into grams, using its molar mass:

1.2 mol * 18 g/mol = 21.6 g

4 0

2 years ago

In your discussion consider a SN2 reaction mechanism concept. Propose a modification of experimental procedure that would improv

Hitman42 [59]

Answer:

Here's what I get

Explanation:

You may have done a Williamson synthesis of guaifenesin by reacting guaiacol with 3-chloropropane-1,2-diol.

A. Mechanism

Step 1

NaOH converts guaiacol into a phenoxide ion.

Step 2

The phenoxide acts as the nucleophile in an SN2 reaction to displace the Cl from the alkyl halide.

B. Improve the yield

You probably carried out the reaction in ethanol solution — a polar protic solvent.

You might try doing the reaction in a polar aprotic solvent— perhaps DMSO.

A polar aprotic solvent does not hydrogen bond to nucleophiles, so they become stronger.

C. Another method of ether synthesis —dehydration of alcohols

Sulfuric acid catalyzes the conversion of primary alcohols to ethers.

This is also a nucleophilic displacement reaction.

Protonation of the OH converts it into a better leaving group.

Attack by a second molecule of alcohol forms the protonated ether.

A molecule of water then removes the proton.

6 0

3 years ago

A 34.53 ml sample of a solution of sulfuric acid, h2s04, reacts with 27.86 ml of 0.08964 m naoh solution. calculate the molarity

Gnoma [55]

The balanced equation between NaOH and H₂SO₄ is as follows
2NaOH + H₂SO₄ ---> Na₂SO₄ + 2H₂O
stoichiometry of NaOH to H₂SO₄ is 2:1
number of moles of NaOH moles reacted = molarity of NaOH x volume
number of NaOH moles = 0.08964 mol/L x 27.86 x 10⁻³ L = 2.497 x 10⁻³ mol
according to molar ratio of 2:1
2 mol of NaOH reacts with 1 mol of H₂SO₄
therefore 2.497 x 10⁻³ mol of NaOH reacts with - 1/2 x 2.497 x 10⁻³ mol of H₂SO₄
number of moles of H₂SO₄ reacted - 1.249 x 10⁻³ mol
Number of H₂SO₄ moles in 34.53 mL - 1.249 x 10⁻³ mol
number of H₂SO₄ moles in 1000 mL - 1.249 x 10⁻³ mol / 34.53 x 10⁻³ L = 0.03617 mol
molarity of H₂SO₄ is 0.03617 M

6 0

3 years ago

Calculate the average atomic mass of element X using the table below. Then use the periodic table to identify the element. Separ

Ksenya-84 [330]

Answer:

126.8, Iodine

Explanation:

mass ×abundance/100
(126.9045×80.45/100)+(126.0015×17.23/100)+(128.2230×2.23/100)
102.1+21.7+3=126.8

IODINE has an atomic mass of 126.8 or 126.9

4 0

2 years ago