what source of electrical energy have scientists been unable to use?

Answer:

correct answer i C i think so

Answer:

Safely throw away the liquids and get new ones.

Explanation:

Not A  because

you shouldn't smell them cause it could be toxic and hurt you

Not B

you should never guess which chemical are which cause if your not correct and use the wrong one you could have a chemical reaction

Not C

you cant mix random liquids it could make a chemical reaction to exploded ore worse create a hurtful gas

Answer:

The correct answer is 12.58 grams.

Explanation:

Based on the given information, the electrolysis equation will be,

Al³⁺ + 3e⁻ ⇔ Al

1 mol of Al needs 3 moles of electron, and the value for 1 mole of electron is 96485 C.

Thus, 1 mole of Al needs 3 × 96485 C = 289455 C

Now the amount of charge passed is,

T = 2.5 hours

= 2.5 × 3600 s = 9 × 10³ s

Q = Current × Time

= 15A × 9 × 10³ s

= 13.5 × 10⁴ C

The moles of Al plated will be,

= 13.5 × 10⁴ / 289455

= 0.4664 mol

The molecular mass of Al is 26.98 grams per mole

Now the mass of Al will be,

= Number of moles × Molecular mass

= 0.4664 × 26.98

= 12.58 grams

Answer: The half-reactions represents reduction are as follows.

Explanation:

A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element  takes place is called reduction-half reaction.

For example, the oxidation state of Cr in [tex]Cr_{2}O^{2-}_{7}[/tex] is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.

[tex]Cr_{2}O^{2-}_{7} + 3 e^{-} \rightarrow Cr^{3+}[/tex]

Similarly, oxidation state of Mn in [tex]MnO^{-}_{4}[/tex] is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.

[tex]MnO^{2-}_{4} + 5 e^{-} \rightarrow Mn^{2+}[/tex]

Thus, we can conclude that half-reactions represents reduction are as follows.

Answer:

+2

Explanation:

I am first with correct answer

Answer:

the oxidation state of iron in FeC2O4 is +2

Answer:

93.4 mL

Explanation:

Let's state the reaction:

2AgNO₃ +  Na₂CO₃  →   Ag₂CO₃  +  2NaNO₃

We determine the moles of sodium carbonate:

0.3572 g . 1mol / 105.98g = 3.37×10⁻³ moles

Ratio is 1:2. We say:

1 mol of sodium carbonate react to 2 moles of silver nitrate

Then, our 3.37×10⁻³ moles of carbonate may react to: 3.37×10⁻³ . 2

= 6.74×10⁻³ moles

If we convert to mmoles → 6.74×10⁻³ mol . 1000 mmol / mol = 6.74 mmol

Molarity is mol/L but we can use mmol /mL

6.74 mol / volume in mL = 0.07216 M

6.74 mol / 0.07216 M = volume in mL → 93.4 mL

Answer:

9.8 L

Explanation:

The reaction that takes place is:

At STP, 1 mol of any gas occupies 22.4 L.

We calculate how many moles are there in 2.5 L of CH₄ at STP:

Then we convert CH₄ moles into H₂ moles, using the stoichiometric coefficients of the reaction:

Finally we calculate the volume that 0.44 moles of H₂ would occupy at STP:

Answer:

hakdog

Explanation:

pangitag lainbbbsjsbshsisbsjsbshxx

Answer:

B. infrared

hope this helps

have a good day :)

Explanation:

Explanation:

bdjdiififjc mfkxkdkd has also had a good time in the

Answer:

B

Explanation:

Answer:

The difference between the three classes depends on where the force is, where the fulcrum is and where the load is. In a first class lever, the fulcrum is located between the input force and output force. In a second class lever, the output force is between the fulcrum and the input force. write the class of lever.

Explanation:

The organ system has been defined as the collective working of the organs for performing a specified task. Each organ system has been assigned a major task to be performed.

The function of the following organ systems have been:

For more information about organ system, refer to the link:

https://brainly.com/question/12825206

Answer:

There are four atoms and two lone pairs around the central atom, which corresponds to AX4E2 or square planar. The shape of XeF4 is square planar.

Explanation:

I hope it's help u

Answer:

823.7g

Explanation:

Using the formula as follows:

Q = m × c × ∆T

Where;

Q = amount of heat (J)

m = mass of substance (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C)

Using the information given in this question as follows:

Q = 6,400 J

m = ?

c of soil = 0.840 J/g°C

∆T = 9.25°C

Using Q = mc∆T

m = Q ÷ c∆T

m = 6,400 ÷ (0.840 × 9.25)

m = 6400 ÷ 7.77

m = 823.7g

Answer:

There are 823.68 grams.

Explanation:

Calorimetry is responsible for measuring the amount of heat generated or lost in certain physical or chemical processes.

Between heat and temperature there is a relationship of direct proportionality. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat by the mass of the body. In summary, the amount of heat Q that receives or transmits a mass m of a substance with specific heat C to raise its temperature from T1 to T2 is given by the formula:

Q= C*m* (T2- T1) = C*m* ΔT

In this case:

Replacing:

6400J= 0.840 [tex]\frac{J}{g*C}[/tex] *m* 9.25 C

Solving:

[tex]m=\frac{6400 J}{0.840 \frac{J}{g*C} *9.25 C}[/tex]

m=823.68 grams

There are 823.68 grams.

Answer:

I think you forgot to post the question or picture

Explanation:

2H2O and 0.722g of Na3PO4.12H20 mix with water forming 500 mL of solution, how many grams of Ba3(. ... Forming 500 ML Of Solution, How Many Grams Of Ba3(PO4)2 Precipitate?

When 0.421 g of BaCl₂ · 2 H2O and 0.722g of Na₃PO₄ · 12 H₂O mix with water forming 500 mL of solution then 0.003 mol/L of Ba₃(PO4)₂ precipitate.

Stoichiometry is an important concept which helps us use the balanced chemical equation to measures the amount of reactants and products.

Molarity of solution is the number of moles of solute per liter of solution. Molarity is also called Molar Concentration.

Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]

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

First we have to write the balanced chemical equation

2Na₃PO₄ · 12 H₂O + 3BaCl₂ · 2 H2O → Ba₃(PO4)₂ + 6 NaCl + 30 H₂O

Here 3 moles of BaCl₂ · 2 H2O produce 1 mole of Ba₃(PO4)₂

So,

Number of moles of BaCl₂ · 2 H2O = [tex]\frac{\text{Mass of}\ BaCl_2 . 2H_2O}{\text{Molar mass of}\ BaCl_2. 2H_2O}[/tex]

                                                           =  [tex]\frac{0.421}{244.26}[/tex]

                                                           = 0.017

Number of moles of 2Na₃PO₄ · 12 H₂O = [tex]\frac{\text{Mass of}\ Na_3PO_4. 12H_2O}{\text{Molar mass of}\ Na_3PO_4 . 12H_2O}[/tex]

                                                                 = [tex]\frac{0.722}{380.12}[/tex]

                                                                 = 0.002

Therefore, Na₃PO₄ · 12 H₂O is the limiting reagent.

Now, put the value in above formula to find the molarity

Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]

                    = [tex]\frac{0.0017}{0.5}[/tex]

                    = 0.003 mol/L

Thus, from above conclusion we can say that 0.003 mol/L of Ba₃(PO4)₂ precipitate.

Learn more about the Stoichiometry here: https://brainly.com/question/14935523
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Answer:

Molarity = 0.809 M

mole fraction = 0.047

Explanation:

The complete question is

Calculate the molarity and mole fraction of acetone in a 1.09-molal solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone = 0.788 g/cm3; density of ethanol = 0.789 g/cm3.) Assume that the volumes of acetone and ethanol add.

Solution -

Solution for molarity:

1.09-molal means 1.09 moles of acetone in 1.00 kilogram of ethanol.

1)  

Mass of 1.09 mole of acetone

= 1.09  mol x 58.0794 g/mol = 63.306 g

Density of acetone = 0.788 g/cm3  

Thus, volume of 1.09 moles of acetone = 63.306 g/0.788 g/cm3 = 80.34 cm3

For ethanol

1000 g divided by 0.789 g/cm3 = 1267.427 cm3

Total volume of the solution = Volume of acetone + Volume of ethanol = 80.34 cm3 + 1267.427 cm3 = 1347.765 cm3  = 1.347 L

a) Molarity:

1.09 mol / 1.347 L = 0.809 M

Mole Fraction  

a) moles of ethanol:

1000 g / 46.0684 g/mol = 21.71 mol

b) moles of acetone:

1.09 / (1.09 + 21.71) = 0.047

Answer:

lololol

Explanation:

We are given:

Initial concentration of HA: 0.200 Molar

The acid is 9.4% ionized

Dissociation constant (α) = (Percent Ionized) / 100 = 0.094

Molar concentration of H+ = 0.0188

Let's Chill! (making the ICE box):

Reaction:       HA         ⇄       H⁺      +      A⁻

Initial:           0.200M               -                -

Equilibrium: 0.200(1-α)      0.200α       0.200α

while we're here, let's confirm the given equilibrium concentration of H⁺ ions

from the table here, we can see that the equilibrium concentration of H⁺ ions is 0.200α, we know that α = 0.094

[H⁺] = 0.200α = 0.200 * 0.094 = 0.0188 M

which means that we're on the right track

We're basically scientists at this point (finding the dissociation constant):

Acid dissociation is nothing but the equilibrium constant, but for the dissociation of Acids

From the reaction above, we can write the equation of the acid dissociation constant:

Ka = [H⁺][A⁻] / [HA]

now, let's take the values from the 'equilibrium' row of the ice box the plug those in this equation

Ka = (0.200α)(0.200α) / [0.200(1-α)]

Ka = (0.200α)²/[0.200(1-α)]

plugging the value of α

Ka = (0.200*0.094)² / [0.200(0.906)]

Ka = (0.0188)² / 0.1812

Ka = 1.95 * 10⁻³

Answer:

... Sorry I don't know the answer

The pOH of the solution containing 9.8×10⁻³ M of hydrogen ion concentration, [H⁺] is 11.99

First, we shall determine the hydroxide ion concentration [OH⁻] in the solution. Details below:

[H⁺] × [OH⁻] = 10¯¹⁴

9.8×10⁻³ × [OH⁻] = 10¯¹⁴

Divide both side by 9.8×10⁻³

[OH⁻] = 10¯¹⁴ / 9.8×10⁻³

[OH⁻] = 1.02×10⁻¹² M

Finally, we shall determine the pOH of the solution. Details below:

pOH = -Log [OH⁻]

pOH = -Log 1.02×10⁻¹²

pOH = 11.99

Thus, from the above calculation, we can conclude that the pOH of the solution is 11.99

Learn more about pOH:

https://brainly.com/question/14023417

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Answer: False

Explanation:

Hope this help

Answer:

True.

Explanation:

Every child will contain the same number of chromosomes as the parents (otherwise they wouldn't be considered the same species). Additionally, animals can only mate with a species containing the same number of chromosomes as themselves. This means if the offspring of the parents had a different number fo chromosomes the offspring would be unable to mate with animals of it's own species.

Answer:

The substances made from polyvinyls are generally brittle and hard. This property prevails because the polymer strands present in the polyvinyls form a very regular and well-organized packing composition in the solid-state. The Van der Waals associations between the strands make the substance brittle. To make the substance soft and suitable to use as a raincoat, the incorporation of small molecules is done within the molten polymer before the hardening of the plastic.

These polymer strands act as plasticizers and prevent the strands of polymer from forming a hard and brittle conformation.

Answer:

Single displacement

Explanation:

Answer:

The original7 fluid oz. 70% tincture of iodine is diluted to 98 fluid oz. to obtain a 5% solution.

Explanation:

Dilution is a technique employed in experimental sciences such as chemistry and biochemistry as well as in medicine to obtain a less concentrated solution from a more concentrated one.

The dilution formula is the most important formula required in dilution. The dilution formula is given as: C1V1 = C2V2

Where C1 is the initial concentration of the stock solution;

V1 is the volume of the stock solution required;

C2 is the final concentration of the diluted solution to be prepared;

V2 is the final volume of the diluted solution.

Using the dilution formula to determine the answer to the above question:

C1 = 70% = 0.7; V1 = 7 fluid oz.; C2 = 5% = 0.05; V2 = ?

To determine V2, it is made subject of the dilution formula:

V2 = C1V1/C2

V2 = (0.7 × 7) / 0.05

V2 = 98 fluid oz.

Therefore, the original7 fluid oz. 70% tincture of iodine is diluted to 98 fluid oz. to obtain a 5% solution.

Answer:

Yes.

Explanation:

Yes, I agree with Bryce and his lab partner because titration is completed when the solution changes its colour. Add chemical from the burette until the solution change its colour so then calculate the amount of chemical is used from the burette and the time at which the titration is completed. Always be careful for calculating the titration in order to get accurate data of the solution.