All categories

3 years ago

Choose true or false

Chemistry

1 answer:

ohaa [14]3 years ago

8 0

Explanation:

Grignard reagent reacts with ketones. Upon chemical reaction of acetone and Grignard reagent there will be formation of tertiary alcohol.

1). So the statement, acetone cannot be used as a solvent because the Grignard reagent will react with its carbonyl, instead of reacting with the planned synthesis carbonyl is true.

2). Tetrahydrofuran is not a suitable solvent for the Grignard reaction because his oxygen may form complexes with the Mg, deactivating the Grignard is a false statement.

3). Phenol can be used as a solvent in Grignard reaction as long as is anhydrous and moisture is kept out of the system with a drying tube with drierite is false statement.

4). Syringes are used in the Grignard experiment to avoid mixing all the reagents is false statement.

5). We use syringes to inject the reagents through a septum preventing moisture to enter the system is true statement.

You might be interested in

5. Citric acid is the main acid present in lemon juice. However vitamin C, or ascorbic acid is

aev [14]

In the titration of lemon juice, the presence of ascorbic acid means the concentration of citric acid you calculated is higher.

An acid-base titration is a common way to determine the unknown concentration of an acid, given we know the concentration of the base and determine the spent volume in the titration. Let's consider the neutralization reactions that take place in a mixture of citric acid and ascorbic acid.

Citric acid titration :

3 NaOH(aq) + H₃C₆H₅O₇(aq) → Na₃C₆H₅O₇(aq) + 3 H₂O(l)

Ascorbic acid titration:

NaOH(aq) + HC₆H₇O₆(aq) → NaC₆H₇O₆(aq) + H₂O(l)

If we titrated a solution that contained only citric acid, we can relate through stoichiometry the moles and concentration of citric acid. However, if the solution also contained ascorbic acid, we would have to spend more NaOH to titrate it. Since more NaOH would react, we would conclude that there is more citric acid to react, calculating a higher concentration of the same.

In the titration of lemon juice, the presence of ascorbic acid means the concentration of citric acid you calculated is higher.

You can learn more about titration here: brainly.com/question/2728613

7 0

2 years ago

How much heat is needed to melt 100.0 grams of ice that is already at 0°C?

Jet001 [13]

Taking into account the definition of calorimetry and latent heat, the heat needed to melt 100.0 grams of ice that is already at 0°C is 33,400 J (option A).

<h3>Calorimetry</h3>

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

<h3>Latent heat</h3>

Latent heat is defined as the energy required by a quantity of substance to change state.

When this change consists of changing from a solid to a liquid phase, it is called heat of fusion and when the change occurs from a liquid to a gaseous state, it is called heat of vaporization.

In this case, the heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to

Q = m×L

where L is called the latent heat of the substance and depends on the type of phase change.

<h3>Heat needed to melt ice</h3>

In this case, you have to melt the ice into liquid water.Being the specific heat of melting of ice is 334 J/g, the heat needed to melt 100 grams of ice is calculated as:

Q= 100 grams× 334 J/g

Solving:

In summary, the heat needed to melt 100.0 grams of ice that is already at 0°C is 33,400 J (option A).

Learn more about calorimetry:

brainly.com/question/15224761

#SPJ1

4 0

1 year ago

Please helpp: All things that are acidic will eventually produce ___ in an aqueous solution?

BARSIC [14]

Answer:

Protons / H+ ions

Explanation:

8 0

3 years ago

Read 2 more answers

What is the energy of light associated with a transition from n=3 to n=8 in a hydrogen atom? Does this represent absorption or e

solong [7]

Explanation:

Energy levels to be n = 8 and n = 3. Rydberg's equation will allow you calculate the wavelength of the photon emitted by the electron during this transition

1λ = R ⋅ (1/nf^2 − 1/ni^2)

where,

λ - the wavelength of the emitted photon

R - Rydberg's constant = 1.0974 x 10^7m

nf - the final energy = 8

ni - the initial energy level = 3

1/λ = 1.0974 x 10^7 * (1/8^2 − 1/3^2)

= -1.05x 10^6 m.

Using Heinsberg's equation,

E = (h * c)/λ

Calculating the energy of this transition you'll have to multiply Rydberg's equation by h * c

where,

h - Planck's constant = 6.626 x 10^−34 Js

c - the speed of light = 3.0 x 10^8 m/s

So, the transition energy, E = (6.626 x 10^−34 * 3 x 10^8) * -1.05x 10^6

= -2.08 x 10^-19 J.

When an electron transitions from a less excited state to a excited state (higher energy orbit), the difference in energy is absorbed as a photon.

The energy is negative which means energy is lost or dissipated to the surroundings. Therefore, an absorption of photons.

8 0

3 years ago

(41 POINTS!!) What is the relationship between the Kuiper Belt and the status of Pluto today?

Olin [163]

Pluto's orbit intersects the Kuiper Belt. Hope this helps.

3 0

3 years ago

Read 2 more answers