Find the concentration of Pb2 (aq) in ppm by mass of a 1.13 L sample of contaminated water that was assayed by adding NaI(s) and obtaining 55.1x10-3 g of PbI2(s) precipitate. Assume that Pb2 (aq) is completely precipitated as PbI2(s). The molar mass of PbI2(s) is 461.01 g/mol. Assume that the density of the solution is 1.00 kg/L. Give the answer with 3 or more significant figures.

Answer:

John Dalton

Explanation:

Explanation:

If bunsen burner gave a luminous flame then there will deposition of soot at the bottom of the test tube which is actually pure carbon.

This deposition of soot actually depicts that there is incomplete combustion reaction that has taken place.

Also, the deposition of soot will provide a limited supply of oxygen to the reaction that has been calculated.

Therefore, in order to avoid any formation of soot it is advisable to adjust the burner flame till it produces a blue flame.

Answer:

D

Explanation:

According to the law of conservation of mass, matter can neither be created nor destroyed. The implication of this is that the total mass of reactants should be equal to the total mass of products.

There should be equal masses of reactants and products on both sides of the reaction equation. This most important condition is only satisfied by option D.

Answer:

Explanation:

mass = 400 grams * [1 kg/1000 grams] = 0.400 kg

c = 387 Joules / (oC * kg)

Δt = 55 - 30 = 25 oC

E = m*c * Δt

E = 0.4 * 387 * 25

E = 3870 Joules

The nucleons are havier in sub atomic particle like neutrons and protons.

fun fact i read in a book even 1cm³ of nucleons are around 2 million Kg which you can't pick up by hand even by machines like buldozer.

Answer:

25.5kg or about 56.2lbs

Explanation:

At 4°C pure water has a mass of about 1 kg/​liter.

So, if there was 25.5 L of water it would be 25.5kg or about 56.2lbs.

Answer:

The red litmus turns to blue

Explanation:

Hope it helps

Answer:

As organisms release energy during cellular respiration, carbon dioxide is produced from the carbon in energy storage molecules. ... Carbon dioxide in the biodome decreased because decomposers decreased which means there was a decrease in cellular respiration overall.

Explanation:

Carbon dioxide is "a colorless, odorless gas that is present in the atmosphere and is formed when any fuel containing carbon is burned".

Atmosphere is "a mixture of gases that includes about 78% nitrogen and 21% oxygen at Earth's surface".

Fuel is "a substance which upon combustion produces a usable amount of energy".

When the population of decomposer decreased, the amount of carbon dioxide in the biodome decreased drastically. The carbon dioxide that used to be in the air (abiotic matter) is now in another part of the ecosystem and the carbon remained constant.

Hence, Carbon dioxide decreased in the air (abiotic matter) of the biodome.

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Explanation:

i think the answer is A ........ hope this helps

Answer:

See Explanation

Explanation:

In electrophilic aromatic substitution, the benzene ring undergoes substitution when it is reacted with suitable electrophiles.

The products of electrophilic aromatic substitution depends on the substituents already present on the benzene ring. Some substituents activate the ring towards electrophilic substitution and direct the incoming electrophile to the ortho and para positions on the ring while some substituents deactivate the benzene ring towards electrophilic substitution and direct the incoming electrophlle to the meta position on the ring.

The amide substituent is moderately activating and is an ortho, para director hence the products shown in the mage attached to this answer.

Answer:If two heterozygous parents with a genotype of Yy are crossed, the possible combination of genotypes in their offspring would be YY, Yy, Yy, and yy. Therefore, the genotypic ratio of the offspring produced is 1:2:1.

Explanation:If two heterozygous parents with a genotype of Yy are crossed, the possible combination of genotypes in their offspring would be YY, Yy, Yy, and yy. Therefore, the genotypic ratio of the offspring produced is 1:2:1.

Answer:

2x10⁻⁴cm and 7.9x10⁻⁵ inches

Explanation:

Micrometer, μm, is an unit of length. Could be related with another units of lenght as, for example:

1.0μm = 1x10⁻⁴cm

1.0μm = 3.93701x10⁻⁵ inches

That means, 2.0μm are:

2.0μm * (1x10⁻⁴cm / 1μm) = 2x10⁻⁴cm

And:

2.0μm * (3.93701x10⁻⁵ inches / 1μm) = 7.9x10⁻⁵ inches

Answer:

The correct answer is 0.157 M.

Explanation:

The chemical equation of the mentioned reaction is, 3NaOH + H₃PO₄ ⇄ Na₃PO₄ + 3H₂O The molarity of NaOH given is 0.2 M, the volume of NaOH given is 23.6 ml or 23.6 × 10⁻³ L. The moles of NaOH can be determined by using the formula, Moles of NaOH = Volume of NaOH × Molarity Moles of NaOH = 23.66 × 10⁻³ L × 0.2 M = 0.00472 moles Based on the reaction, 3 moles of NaOH needs 1 mole of H₃PO₄. So, 0.00472 moles of NaOH will require, 0.00472/3 = 0.0015733 moles.

The concentration or molarity of the H₃PO₄ will be, [H₃PO₄] = Moles of H3PO4/Volume of H₃PO₄ in liters (Volume of H₃PO₄ given is 10 ml of 10 × 10⁻³L) = 0.0015733 moles/ (10 × 10⁻³ L) = 0.157 M

Answer: The value of [tex]K_{eq}[/tex] for this reaction is 1.578.

Explanation:

Given: Initial moles of [tex]N_{2}O_{4}[/tex] = 0.4 mol

Volume = 1.00 L

Therefore, initial concentration of [tex]N_{2}O_{4}[/tex] is calculated as follows.

[tex]Concentration = \frac{moles}{volume}\\= \frac{0.4}{1.0 L} mol\\= 0.4 M[/tex]

Now, ICE table for the given reaction equation is as follows.

                     [tex]N_{2}O_{4}(g) \rightleftharpoons 2NO_{2}[/tex]

Initial:               0.4               0

Change:           -x                +2x

Equib:  0.4 - x = 0.0055       2x

Hence, the value of x is calculated as follows.

0.4 - x = 0.0055

x = 0.4 - 0.0055

= 0.3945

Now, the [tex][NO_{2}][/tex] is calculated as follows.

2x = [tex][NO_{2}][/tex] = [tex]2 \times 0.3945 = 0.789[/tex]

Therefore, [tex]K_{eq}[/tex] for the given reaction is calculated as follows.

[tex]K_{eq} = \frac{[NO_{2}]^{2}}{[N_{2}O_{4}]}\\= \frac{(0.789)^{2}}{(0.3945)}\\= 1.578[/tex]

Thus, we can conclude that [tex]K_{eq}[/tex] for this reaction is 1.578.

Answer:

1.61

Explanation:

This is the reaction of respiration. Hence, the complete reaction is:

C₆H₁₂O₆ + O₂ → 6CO₂ + 6H₂O

Respiration is defined as a metabolic process wherein the living cells of an organism obtain energy (in the form of ATP) by taking in oxygen and releasing carbon dioxide from the oxidation of complex organic compounds. There are two forms of respiration: aerobic and anaerobic.

Aerobic respiration occurs in the presence of oxygen, while anaerobic respiration occurs in the absence of oxygen.

Because it generates the energy required for body function, respiration is significant. It gives the cells oxygen and releases harmful carbon dioxide. Hence, the reaction of cellular respiration is:

                           C₆H₁₂O₆ + O₂ → 6CO₂ + 6H₂O

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Answer:

The answer is C. the child receives half of is genetic information from each parent

Explanation:

hope this helps enjoy

Answer:

0.00818 moles

Explanation:

The group corresponding to alkali metal, alkali earth metal, halogen, and noble gas is IA,IIA, 17, 18 group respectively.

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Answer:

c. alkyne.

Explanation:

Hello there!

In this case, according to the attached file, it turns out possible for us to say that alkanes have only single-bonded carbon atoms, alkenes have two double-bonded carbon atoms and alkynes have two triple-bonded carbon atoms.

In such a way, according to the aforementioned definition, we infer that that an organic compound that contains only carbon and hydrogen and a triple bond (all the other bonds are single bonds) is classified as c. alkyne.

Regards!

Answer: The [tex]K_{sp}[/tex] value for calcium hydroxide at this temperature is [tex]1.08 \times 10^{-4}[/tex].

Explanation:

Given: Mass of [tex]Ca(OH)_{2}[/tex] = 0.225 g

Volume = 0.100 L

As moles is the mass of substance divided by its molar mass.

So, moles of [tex]Ca(OH)_{2}[/tex] (molar mass = 74 g/mol) is calculated as follows.

[tex]Moles = \frac{mass}{molar mass}\\= \frac{0.225 g}{74 g/mol}\\= 0.003 mol[/tex]

Molarity is the number of moles of substance present in a liter of solution.

Hence, molarity of given solution will be as follows.

[tex]Molarity = \frac{moles}{Volume (in L)}\\= \frac{0.003 mol}{0.1 L}\\= 0.03 M[/tex]

The equation for dissociation of  [tex]Ca(OH)_{2}[/tex] is as follows.

[tex]Ca(OH)_{2} \rightarrow Ca^{2+} + 2OH^{-}[/tex]

This means that [tex][Ca^{2+}] = 0.03[/tex] and [tex][OH^{-}] = 2 \times 0.03 = 0.06[/tex]. Hence, [tex]K_{sp}[/tex] value for this reaction is calculated as follows.

[tex]K_{sp} = [Ca^{2+}][OH^{-}]^{2}\\= (0.03) \times (0.06)^{2}\\= 1.08 \times 10^{-4}[/tex]

Thus, we can conclude that the [tex]K_{sp}[/tex] value for calcium hydroxide at this temperature is [tex]1.08 \times 10^{-4}[/tex].

Answer:

NCl₃

Explanation:

From the question given above, the following data were obtained:

Mass of nitrogen (N) = 0.77 mg

Mass of chlorine (Cl) = 6.61 mg

Empirical formula =?

The empirical formula of the compound can be obtained as follow:

N = 0.77 mg

Cl = 6.61 mg

Divide by their molar mass

N = 0.77 / 14 = 0.055

Cl = 6.61 / 35.5 = 0.186

Divide by the smallest

N = 0.055 / 0.055 = 1

Cl = 0.186 /0.055 = 3

Therefore, the empirical formula of the compound is NCl₃

Answer:

2 mol/L

Explanation:

M=Mol of solute/L. of solution

M=20mol/10L of H2O= 2mol/L

Answer:

2mol/L

Explanation:

got it correct on my quiz