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2 years ago

What is the LD50 of a substance?

1 answer:

8 0

<em>In toxicology, the median lethal dose, LD₅₀, LC₅₀ or LCt₅₀ is a measure of the lethal dose of a toxin, radiation, or pathogen. The value of LD₅₀ for a substance is the dose required to kill half the members of a tested population after a specified test duration.</em>

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Hi May I know how to balance this

almond37 [142]

Answer:

2Ba₃(PO₄)₂ +6SiO₂ ⇒ P₄O₁₀ +6BaSiO₃

Explanation:

Equating coefficients, you get ...

aBa₃(PO₄)₂ +bSiO₂ ⇒ cP₄O₁₀ +dBaSiO₃

For Ba: 3a = d

For P: 2a = 4c

For O: 8a +2b = 10c +3d

For Si: b = d

Expressing everything in terms of b and c, we get ...

d = b

a = b/3 = 2c

From the second, b = 6c, so we have ...

a = 2c

b = 6c

c = c

d = 6c

And we can write the equation with c=1 as ...

2Ba₃(PO₄)₂ +6SiO₂ ⇒ P₄O₁₀ +6BaSiO₃

4 0

2 years ago

Complete the following precipitation reactions with balanced molecular, total ionic, and net ionic equations:

Dmitry [639]

Molecular equation

Hg₂(NO₃)₂ (aq) + KI(aq) ⇒Hg₂I₂(s) + 2KNO₃(aq)

Total Ionic equation

Hg²⁺(aq) + 2NO³⁻(aq) + 2K⁺aq) ⇒Hg₂I₂(s) + 2K⁺(aq) + NO³⁻ (aq)

Net Ionic equation

Hg²⁺(aq) + 2I⁻(aq) ⇒ Hg₂I₂(s)

<h3>What is the molecular equation?</h3>

Sometimes, a balanced equation is all that is used to refer to a chemical equation. Any ionic substances or acids are represented using their chemical formulas as neutral compounds in a molecular equation. Each substance's state is described in parenthesis after the formula. A complete ionic equation also contains the spectator ions, whereas a net ionic equation just displays the chemical species that are involved in a reaction.

The steps listed below can be used to determine the net ionic equation for a specific reaction:

Include the states of each chemical in the balanced molecular equation for the reaction.

To know more about the molecular equation, visit:

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4 0

11 months ago

List at least three scientific disciplines related to chemistry mentioned or alluded to in the article. The Ozone Hole

SVETLANKA909090 [29]

Answer: biology, climate Science, astronomy etc.

Explanation:

The scientific disciplines that are related to chemistry mentioned or alluded to in the article are:

• Biology: Biology is a natural science which studies living organisms, and this include their molecular interactions, evolution, physical structure, and chemical processes.

• Astronomy: Astronomy is the study of space, and the universe. In astronomy, the stars, planets, and galaxies are all studied.

• Climate science: Climate science is also referred to as climatology and it's the scientific study of climate.

7 0

3 years ago

In an ionic compound, the size of the ions affects the internuclear distance (the distance between the centers of adjacent ions)

jeyben [28]

Answer:

Li2S> Na2S> K2S> CsS

Explanation:

The lattice energy of ionic species depends on the relative sizes of ions in the ionic compounds. As the size of ions increases, the lattice energy decreases and vice versa.

When the size of the anions are the same, the lattice energy now depends on the relative sizes of the cations. Therefore, since all the compounds are sulphides and the order of magnitude of ionic sizes is: Li^+ < Na^+ < K^+ < Cs^+.

Therefore, the order of decrease in lattice energy is; Li2S> Na2S> K2S> CsS

7 0

2 years ago

1.42 g H2 is allowed to react with 10.4 g N2 , producing 2.14 g NH3 . Part A What is the theoretical yield in grams for this rea

Bad White [126]

Taking into account the reaction stoichiometry, the theorical yield for the reaction is 8.0467 grams of NH₃.

<h3>Reaction stoichiometry</h3>

In first place, the balanced reaction is:

3 H₂ + N₂ → 2 NH₃

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

H₂: 3 moles
N₂: 1 mole
NH₃: 2 moles

The molar mass of the compounds is:

H₂: 2 g/mole
N₂: 28 g/mole
NH₃: 17 g/mole

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

H₂: 3 moles ×2 g/mole= 6 grams
N₂: 1 mole ×28 g/mole= 28 grams
NH₃: 2 moles ×17 g/mole= 34 grams

<h3>Limiting reagent</h3>

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

<h3>Limiting reagent in this case</h3>

To determine the limiting reagent, it is possible to use a simple rule of three as follows: if by stoichiometry 28 grams of N₂ reacts with 6 grams of H₂, 10.4 grams of N₂ reacts with how much mass of H₂?

$mass of H_{2} =\frac{10.4 grams of N_{2}x 6 grams of H_{2} }{28 grams of N_{2}}$

<u><em>mass of H₂= 2.2286 grams</em></u>

But 2.2286 grams of H₂ are not available, 1.42 grams are available. Since you have less mass than you need to react with 10.4 grams of N₂, H₂ will be the limiting reagent.

<h3>Definition of theorical yield</h3>

The theoretical yield is the amount of product acquired through the complete conversion of all reagents in the final product, that is, it is the maximum amount of product that could be formed from the given amounts of reagents.

<h3>Theoretical yield in this case</h3>

Considering the limiting reagent, the following rule of three can be applied: if by reaction stoichiometry 6 grams of H₂ form 34 grams of NH₃, 1.42 grams of H₂ form how much mass of NH₃?

$mass of NH_{3} =\frac{1.42 grams of H_{2} x 34 grams of NH_{3}}{6grams of H_{2} }$

<u><em>mass of NH₃= 8.0467 grams</em></u>

Then, the theorical yield for the reaction is 8.0467 grams of NH₃.

Learn more about the reaction stoichiometry:

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7 0

1 year ago