Name the following straight-chain Alkanes (picture)

To measure the amount of calcium carbonate in a seashell, an analytical chemist crushes a sample of the shell to a fine powder a

andreyandreev [35.5K]

The given question is complete, the complete question is:

To measure the amount of calcium carbonate (CaCO) in a seashell, an analytical chemist crushes a 4.80 g sample of the shell to a fine powder and titrates it to the endpoint with 515. mL of 0.140 M hydrogen chloride (HCl) solution. The balanced chemical equation for the reaction is: 2HCI(a)Co (a) H2Co,(aq) + 2Cl (aq)

What kind of reaction is this?

If you said this was a precipitation reaction, enter the chemical formula of the precipitate.

If you said this was an acid-base reaction, enter the chemical formula of the reactant that is acting as the base.

If you said this was a redox reaction, enter the chemical symbol of the element that is oxidized

Calculate the mass percent of CaCO in the sample. Be sure your answer has the correct number of significant digits.

Answer:

It is an acid-base reaction and the mass percent of CaCo3 is 75.2%.

Explanation:

A chemical reaction in which an insoluble salt produces from two soluble salts is termed as precipitation reaction.

A reaction in which atleast exchange of one proton takes place between the two species is termed as an acid-base reaction.

A reaction in which any of the element has a change in oxidation state is termed as redox reaction.

In the mentioned reaction, there is a transfer of H⁺, no precipitation is forming, and no change in oxidation state taking place, thus, it is an acid-base reaction.

In the acid-base reaction, the base refers to the species that accepts hydrogen ion or proton. In the given case, CO₃²⁻ is accepting H+ ion to become H₂CO₃. Hence, CO₃²⁻ is the base.

In order to calculate mass percent of CaCO₃, first there is a need to find the moles of HCl reacted for a solution,

Moles = Molarity × Volume (L)

Moles = 0.140 mol/L × 515 × 10⁻³ L

Moles = 0.0721 mol

Now from the balanced equation, one mole of CaCO₃ needs two moles of HCl.

So, moles of CaCO₃ reacted will be,

= 1/2 × 0.0721 = 0.03605 mol

The mass of calcium carbonate taking part in reaction will be,

= Moles × Molar mass

= 0.03605 × 100 gram/mole

= 3.6086 gram

Mass% of CaCO₃ = Mass of CaCO₃/Mass of sample × 100

= 3.6086 grams/4.80 grams × 100

Mass % = 75.2%

3 0

3 years ago

and amounts of reactants: 2.01 g salicylic acid + 5.00 mL acetic anhydride (plus 5 drops of 85% phosphoric acid) a) If the densi

irakobra [83]

Answer:

see explanation below

Explanation:

Now. According to the context of this problem, I'm assuming you are doing the synthesis reaction of aspirin, which is a 1:1 ratio and the reaction is:

C7H6O3 + C4H6O3 ------> C9H8O4 + CH3COOH

Now that we know the general reaction, first, let's get the mass of acetic anhydride

m = d*V = 1.08 * 5 = 5.4 g

Now, with the molar mass of each reactants:

MM of SA = 138.12 g/mol

MM of AA = 102.09 g/mol

MM of aspyrin = 180.16 g/mol

Let's calculate now the moles:

moles of SA = 2.01 / 138.12 = 0.015 moles

moles of AA = 5.4 / 102.09 = 0.053 moles

As we can see in the reaction, 1 mole of SA reacts with 1 mole of AA but we have 0.015 of SA and 0.053 of AA, This means that the limiting reagent is the SA, therefore, it will be the first to be consumed in the reaction.

Now the theorical yield of Aspirin is:

m = 0.015 * 180.16 = 2.7024 g

The purpose of the phosphoric acid is to convert the anhydride acetic into an acid form, therefore, the Salycid acid (The OH) can act as nucleophile and react with the carbonile of the anydride. In this way, we can form the aspirin,

6 0

3 years ago

Can Intrusive and Extrusive Igneous rocks form from the same mineral composition?

Annette [7]

No I can’t
EXAMPLE took the test k12

3 0

3 years ago

Which is a metal alloy?

Nikolay [14]

D they are all metals

4 0

3 years ago

A sample of lsd (d-lysergic acid diethylamide, c24h30n3o) is added to some table salt (sodium chloride) to form a mixture. given

spin [16.1K]

1) All the CO2 comes from the C24 H30 N3 O

2) To balance C from CO2 with C from C24, the ratio of cC24 H30 N3 O to CO2 is 24 / 1

3) Convert 1.20 g of CO2 to number of moles

number of moles = mass in grams / molar mass

mass = 1.20 g

molar mass = 12.01 g/mol + 32.00 g/mol = 44.01 g/mol

number of moles = 1.2 g / 44.01 g/mol = 0.0273 mol

4) proportion

1 mol C24 H30 N3 O / 24 mol CO2 = x / 0.0273 mol CO2

=> x = 0.0273 mol CO2 * 1 mol C24H30N3O / 24 mol CO2 = 0.00114 mol C24H30N3O

5) Convert 0.00114 mol C24H30N3O to grams

molar mass = 376.5 g/mol

mass = 0.00114 mol * 376.5 g/mol = 0.429 g

6) mass percent in the mixture

mass percent = (mass of lsd / mass of mixture) * 100 = (0.429g / 1.0g) * 100 = 42.9%

Answer: 42.9%

6 0

3 years ago