The precision of a method is being established, and the
following
data are obtained 22.23, 22.18 22.25, 22.09
and 22.15%, is 22.09% a valid measurement?​

Answer:

A saturated solution is a mixture in which the maximum amount of a given solute has been dissolved into the solvent. ... At this point adding more solute will not change the concentration of the solution; adding more solute will simply result in more solid at the bottom of the solution.

Answer:

will not change

Explanation:

A saturated solution is a mixture in which the maximum amount of a given solute has been dissolved into the solvent. ... At this point adding more solute will not change the concentration of the solution; adding more solute will simply result in more solid at the bottom of the solution.

Answer:

The answers to your questions are given below.

Explanation:

__ NaBr + CaF₂ —> __ NaF + CaBr₂

The above equation can be balance as follow:

NaBr + CaF₂ —> NaF + CaBr₂

There are 2 atoms of F on the left side and 1 atom on the right side. It can be balance by writing 2 before NaF as shown below:

NaBr + CaF₂ —> 2NaF + CaBr₂

There are 2 atoms of Na on the right side and 1 atom on the left side. It can be balance by writing 2 before NaBr as shown below:

2NaBr + CaF₂ —> 2NaF + CaBr₂

Now, the equation is balanced.

Atom >>>> Reactant >>>> Product

Na >>>>>> 2 >>>>>>>>>>> 2

Br >>>>>>> 2 >>>>>>>>>>> 2

Ca >>>>>> 1 >>>>>>>>>>>> 1

F >>>>>>> 2 >>>>>>>>>>>> 2

Answer:

The final units are mol

Explanation:

The units of molar mass are grams per mole, g/mol.

This means that when dividing mass by molar mass, the units of grams cancel each other, leaving only units of moles:

Another way of writing that might help is as follows:

Thus, the final units are moles.

Answer:

9.24

Explanation:

-logofH

Answer:

liquid to gas

Explanation:

when boiling water when evaporating heat is given out

Answer:

4 M

Explanation:

To answer this problem we can use the following formula:

Where the subscript 1 refers to the volume and concentration before diluting, and 2 refers to volume and concentration after diluting.

Meaning that in this case we can write:

We can now solve for C₁:

Answer:

The value of n is 6

Explanation:

The half-reactions of the problem are:

Cr(s) → Cr³⁺ + 3e⁻

Pb²⁺ + 2e⁻→ Pb(s)

To balance the electrons we must multiply the half-reactions as follows:

2 * (Cr(s) → Cr³⁺ + 3e⁻)

3 * (Pb²⁺ + 2e⁻→ Pb(s))

2Cr(s) → 2Cr³⁺ + 6e⁻

3Pb²⁺ + 6e⁻→ 3Pb(s)

In Nernst equation, the value of n are the electrons used to balance the reaction, as in this problem, the electrons are 6:

Answer:

D. Mutation

Explanation:

Mutation is any change or alteration that occurs to the nucleotide sequence of a gene induced during DNA replication or by mutation-causing substances called MUTAGENS.

Mutation can be in the form of addition, removal, or substitution of nitrogenous bases in a DNA molecule. For example, in an original DNA sequence as follows: GAT ATC TGA, the following mutation can occur:

Addition: GAT ATC CTG A

Removal: GAT ATT GA

Substitution: GAT CTC TGA

Given :

It takes 45.60 mL of a 0.225 M hydrochloric acid solution to react completely with 25.00 mL of calcium hydroxide in the given reaction.

2HCl(aq) + Ca(OH)2(aq) --> CaCl2(aq) + 2H2O(l)

To Find :

The molar concentration of the calcium hydroxide solution.

Solution :

From given equation 2 mole of hydrochloric acid react with 1 mole of calcium hydroxide.

So,

[tex]2M_1V_1 = M_2V_2\\\\2\times 0.225 \times 45.60 = M_2 \times 25 \\\\M_2 = \dfrac{20.52}{25}\\\\M_2 = 0.8208 \ M[/tex]

Therefore, molar concentration of the calcium hydroxide solution is 0.8208 M.

Answer:

Molar concentration of the calcium hydroxide solution = 0.2052 M

Explanation:

Volume of HCl = 45.60 mL  = 0.0456 L

Molar concentration of HCl = 0.225 M

Volume of Ca(OH)2 = 25.00 mL  = 0.025 L

No. of moles of HCl = (0.225 M)*(0.0456 L)   = 0.01026 mol

As we know

2 moles of HCl require 1 mole of Ca(OH)2, hence, .01026 moles of HCl will need 0.5*(0.01026) = 0.00513 moles of Ca(OH)2

Molar concentration of Ca(OH)2 = [(0.00513 mol)/(0.025 L)]   = 0.2052 M

Answer:

B the weight of the passengers

Answer:

-1,300 kJ

I don't want to explain it brainly AAAAA

The standard enthalpy of the reaction is the enthalpy change which occurs in a system when a matter is transformed by a chemical reaction under standard conditions. Here the enthalpy of the overall chemical reaction is  -1,300 kJ. The correct option is B.

In any general chemical reaction, the reactants undergo chemical changes to form products. The change in enthalpy is represented as ΔrH and is termed as the reaction enthalpy. It can be calculated by subtracting the sum of enthalpies of all the reactants from that of the products.

ΔrH  = ∑ aiH products - ∑ bi H reactants

Here we should reverse the first reaction and also multiply its ΔH by (- 1):

P₄O₆(s) → P₄(s) + 3O₂(g), ΔH₁' = 1640.1 kJ.

The second reaction is also reversed and also multiply its ΔH by (- 1):

P₄(s) + 5O₂(g) → P₄O₁₀(s), ΔH₂' = - 2940.1 kJ.

If we add the two reactions after modification, we get:

P₄O₆(s) → P₄O₁₀(s).

Therefore,  ΔH = ΔH₁' + ΔH₂' = 1640.1 kJ + (- 2940.1 kJ) = - 1300 kJ.

Thus the correct option is B.

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Answer:

Nitrates compared to sulphates are much more soluble therefore won't form precipitates easily.

Answer:

SEE EXPLANATION

Explanation:

We must first obtain the molar mass of CHCl3 as follows;

CHCl3 = ( 12.01 * 1 )+ (1.008 * 1 ) + ( 35.45 * 3 ) => 119.37 g/mol

Then we obtain the percentage by mass of each element

For Carbon =  ( atomic mass C / molar mass CHCl3 ) * 100

C  =  (12.01 / 119.37 ) * 100

C = ( 0.1006 * 100 )

C =  10.06 %

For Hydrogen :

H = ( atomic mass H / molar mass CHCl3 ) * 100

H = ( 1.008 / 119.37 ) * 100

H = 0.008444 * 100

H = 0.8444 %

For Chlorine :

Cl  ( molar mass Cl3 / molar mass CHCl3 ):

Cl =  ( 3 * 35.5 / 119.37 ) * 100

Cl =  ( 106.5 / 119.37 ) * 100

Cl = 0.8921 * 100

Cl = 89.92%

Answer:

0.01804 M KMnO4 Solution.

Explanation:

3 Percent(w/w) H2O2 Are Sold In Drug Stores As A Disinfectant. ... H2O2 In A Bottle Of Peroxide Solution Was Done By Diluting 1.50 ML To 100 ML With Water, Acidifying With Dilute H2SO4 And Titrating With A 0.01804 M KMnO4 Solution.

Answer:

Molecular formula => C₅H₅O₅

Explanation:

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

Empirical formula = CHO

molar mass of compound = 145 g/mol

Molecular formula =?

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

Molecular formula = Empirical formula × n

Molecular formula = [CHO]ₙ

[CHO]ₙ = 145

[12 + 1 + 16]n = 145

29n = 145

Divide both side by 29

n = 145 / 29

n = 5

Molecular formula = [CHO]ₙ

Molecular formula = [CHO]₅

Molecular formula => C₅H₅O₅

Answer:

2.04x10⁻⁴ mol

Explanation:

First we convert 3.06x10⁻³ grams of glycine into moles of glycine, using its molar mass:

In order to calculate the number of hydrogen moles, we multiply the number of glycine moles by 5, as there are 5 hydrogen moles per glycine mol:

Answer:

1.75 g HCl

Explanation:

First we convert 2.00 g of PCl₅ into moles, using its molar mass:

Then we convert PCl₅ moles into HCl moles, using the stoichiometric coefficients of the equation:

Finally we convert HCl moles into grams, using its molar mass:

Answer:

A. mushroom

Explanation:

Answer:

[tex]SO_3[/tex]

Explanation:

Hello there!

In this case, according to the definition of the empirical formula as the smallest representation of the molecular formula of a chemical compound; for us to determine it, we first need to calculate the moles of sulfur in 40.05 g and those of oxygen in 59.95 g as shown below:

[tex]n_S=\frac{40.05g}{32.07g/mol}= 1.25molS\\\\n_O=\frac{59.95g}{16.00g/mol}=3.75molO[/tex]

Now, we perform the following mole ratios to figure out the subscripts in the empirical formula, by dividing over the fewest number of moles:

[tex]S=\frac{1.25}{1.25}=1 \\\\O=\frac{3.75}{1.25}=3[/tex]

Therefore, the empirical formula turns out:

[tex]SO_3[/tex]

Best regards!

Answer: The percentage of potassium iodide in the sample is 2.63 %.

Explanation:

The chemical equation for the reaction of iodide ions with bromine gas follows:

[tex]I^-+3Br_2+3H_2O\rightarrow 6Br^-+IO_3^-+6H^+[/tex]                (i)

The chemical equation for the reaction of iodate ions with barium ions follows:

[tex]Ba^{2+}+2IO_3^-\rightarrow Ba(IO_3)_2[/tex]                 ......(ii)

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Given mass of barium iodate = 0.0596 g

Molar mass of barium iodate = 487.13 g/mol

Using equation 1:

[tex]\text{Moles of barium iodate}=\frac{0.0596 g}{487.13 g/mol}\\\\\text{Moles of barium iodate}=1.22\times 10^{-4} moles[/tex]

By Stoichiometry of the reaction (ii):

1 mole of barium iodate is produced by 2 moles of iodate ions

So, [tex]1.22\times 10^{-4} moles[/tex] of barium iodate will be produced by [tex]\frac{2}{1}\times 1.22\times 10^{-4} =2.44\times 10^{-4}moles[/tex] of iodate ions

By the stoichiometry of the reaction (i):

1 mole of iodate ions are produced by 1 moles of iodine ions

So, [tex]2.44\times 10^{-4} moles[/tex] of iodate ions will be produced by [tex]\frac{1}{1}\times 2.44\times 10^{-4} =2.44\times 10^{-4}moles[/tex] of iodine ions

Moles of potassium iodide = Moles of iodide ions = [tex]2.44\times 10^{-4}[/tex]

Since, the molar mass of potassium iodide = 166 g/mol

Using equation 1:

[tex]\text{Mass of potassium iodide}=2.44\times 10^{-4}mol\times 166 g/mol\\\\\text{Mass of potassium iodide}=0.0405 g[/tex]

To calculate the percentage by mass of a substance, the equation used is:

[tex]\text{Percent by mass}=\frac{\text{Mass of a substance}}{\text{Mass of solution}}\times 100[/tex]

Mass of a solution = 1.54 g

Mass of potassium iodide = 0.0405 g

Using above equation:

[tex]\text{Percent potassium iodide}=\frac{0.0405 g}{1.54g}\times 100\\\\\text{Percent potassium iodide}=2.63\%[/tex]

Hence, the percentage of potassium iodide in the sample is 2.63 %.

Expressing the results of potassium iodide in percentage = 2.63%

The chemical reaction of iodine ions with Bromine gas can be expressed as :

I⁻  + 3Br₂  + 3H₂O  -- > 6Br⁻ + IO₃ + 6H⁺ ----- ( 1 )

Chemical reaction between iodate ions with barium ions  can be expressed as :  Ba²⁺  + 2IO⁻₃ ------> Ba ( IO₃ )₂   --------- ( 2 )

Step 1 : Calculate the number of Barium iodate moles

mass of Barium iodate = 0.0596 g

molar mass of Barium iodate = 487.13 g/mol

from equation ( 1 )

moles of Barium iodate = ( 0.0596 ) / ( 487.13 ) = 1.22 * 10⁻⁴ moles

also from equation ( 1 ) the moles of potassium iodide = moles of iodide ions

= 2.44 * 10⁻⁴

molar mass of potassium iodide = 166 g/mol

Next step : Determine the mass of potassium iodide

moles of potassium * molar mass

= 2.44 * 10⁻⁴  * 166 g/mol  = 0.0405 g

Final step : Determine the percentage of potassium iodide in the solution

Percentage = ( mass of potassium iodide / mass of solution ) * 100

                   = ( 0.0405 / 1.54 ) * 100

                   = 2.63%

Hence we can conclude that potassium iodide in percentage = 2.63%

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Explanation:

Na3PO4+ FeCl3 = 3NaCl + FePO4

Hope it will help :)❤

The net ionic equation is found to be balanced by both mass and charge. There are equal masses of each element on the product and reactant sides in a balanced net ionic equation.

A chemical equation which shows only those elements, compounds, and ions which are directly involved in the chemical reaction is defined as the net ionic equation. The net ionic equation give us information about the ions that exists in aqueous medium.

A net ionic equation does not consider the spectator ions. The ions which do not participate in chemical reactions and are seen on both sides of the reactions are called spectator ions.

The complete ionic equation for the given reaction is:

3Na⁺ (aq) + PO₄³⁻ (aq) + Fe³⁺ (aq) + 3Cl⁻ (aq) → 3Na⁺ (aq) + 3Cl⁻ (aq) + FePO₄ (s)

The net ionic equation is:

PO₄³⁻ (aq) + Fe³⁺ (aq) → FePO₄ (s)

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Answer:

True

Explanation:

I learned about it a few years ago

Answers:

1. firstly Start numbering from that carbon atom which would be nearest to chlorine .

2. then if u observed properly , both chlorine is attached are attached to 2nd carbon atom.

3.but in first one chlorine is on the left side

whereas in the second one chlorine right side.

p.s:

1. well, were u have number carbon three in above pic take it as C1 than C2( if u observed it is were Cl is attached to C2 ) than C3 ,C4.

2. Then similarly in second molecules where u have number C3 in above pic take it as C1 than C2 (if u observed , again Cl is attached to C2 but this time it is one on opposite sides.

now imagine if u kept first molecules on second one.

matching C1 C2 C3 C4 of first molecules with

C1 C2 C3 C4 of second molecule .

u will observed that in both of them Cl is on C2 but they in exactly opposite position

Explanation:

Enantiomers are a pair of molecules that exist in two forms that are mirror images of one another but cannot be superimposed one upon the other.

Answer:

False

Explanation:

A liquid has a definite shape and takes on the volume of its container. A gas has both the shape and the volume of its container. The particles in a gas cannot be compressed into a smaller volume. Liquids tend to contract when heated.

Hope this helps

Answer:

reactivity

Explanation:

for example atoms in group 7 react by gaining 1 electron to become stable but they do not have the same number of energy levels

Answer:

Number of different animals

Explanation:

Number of different animals is not an abiotic factor that influences an ecosystem rather it is  a biotic factor.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.

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Answer:

0.3832

Explanation:

Givens

m = 437.2 grams

c = ?

delta t = 69.8 - 19.3

H = 8460 J

Formula

H = m*c*Δt

Solution

8460 = 437.2 * c * (69.8 - 19.3)

8460 = 437.2 * c * 50.5

8460 = 22078.6 * c

c = 8460 / 22078,6

c = .3832 J / (oC * gr)

Answer: true

Explanation: