An electromagnet is created by
A. putting a piece of soft iron in an outlet.
B. brushing a piece of steel with a soft cloth.
C. running electric current through a coiled, conductive wire.
D. rubbing two pieces of metal together quickly.

Answer:

pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.32 ) = 6.32

Explanation:

Given 4.3 x 10⁻⁷M H₂CO₃ (Ka1 = 4.2 x 10⁻⁷ &  Ka2 = 4.8 x 10⁻¹¹)

Note: The Ka2 value for the 2nd ionization step is so small (Ka2 = 4.8 x 10⁻¹¹) It will be assumed all of the hydronium ions (H⁺) come from the 1st ionization step.  

1st Ionization step

                    H₂CO₃        ⇄   H⁺ + HCO₃⁻

C(initial)     4.3 x 10⁻⁷             0         0

ΔC                   -x                  +x        +x

C(final)      4.3 x 10⁻⁷ - x         x          x

Note: the 'x' value in this analysis can not be dropped as the Conc/Ka value is less than 10². In this case he C/Ka ratio* (4.3E-7/4.2E-7 ≈ 1)  is far below 10².

So, one sets up the equilibrium equation to be quadric and the x-value can be determined.

Ka1 = [H⁺][HSO⁻]/[H₂SO₃] = (x)(x)/(4.3 x 10⁻ - x) = x²/(4.3 x 10⁻⁷ - x) = 4.2 x 10⁻⁷

=>   x² = 4.2 x 10⁻⁷(4.3 x 10⁻⁷ - x)

=>   x² + 4.2 x 10⁻⁷x - 1.8 x 10⁻¹³ = 0              

      a = 1, b = 4.2 x 10⁻⁷, c = - 1.8 x 10⁻¹³

x = b² ± SqrRt(b² - 4(1)(-1.8 x 10⁻¹³ / 2(1) =  4.75 x 10⁻⁷

x = [H⁺] = 4.75 x 10⁻⁷

pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.4 ) = 6.4

______________________

* The Concentration/Ka-value is the simplification test for quadratic equations used in Equilibrium studies. If the C/Ka > 100 then one can simplify the C(final) by dropping the 'x' if used in this type analysis. However, if the C/Ka value is < 100 then the x-value must be retained and the solution is determined using the quadratic equation formula.

for ax² + bx + c = 0

x = b² ± SqrRt(b² - 4ac) / 2a

Answer:

Explanation:

Find the pH of a 0.0025 M HCl solution. ... The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation

0.00003 in scientific notation would be 3 × 10⁻⁵.

The scientific notation of a number is represented as a coefficient multiplied by 10 raised to an appropriate exponent.  0.00003 can be expressed in scientific notation as [tex]3\times 10 ^{-5}[/tex].

Scientific notation is a simple and standardised approach to express extremely big or extremely small numbers. Its foundation is the idea that a number can be expressed as a coefficient times a power of 10. The exponent indicates how many places the decimal point must be moved to get the original value, while the coefficient is normally an integer between 1 and 10 (inclusive of 1 but exclusive of 10). To write 0.00003 in scientific notation, we need to move the decimal point five places to the right to make the coefficient between 1 and 10. 0.00003 can be expressed in scientific notation as [tex]3\times 10 ^{-5}[/tex].

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Answer:

Explanation:

Understand that a substance's specific heat (C) is a property that can be used to ... Calculate the heat required to melt 25.7 g of solid methanol at its melting point. ... How many moles of NH4NO3 must be dissolved in water so that 88.0 kJ of heat ... to vaporize 54.0 g of ethanol (C2H5OH) if AHvap for ethanol = 43.5. kJ/mol?

Answer:

When sodium chloride dissolves in water to make a saturated solution there is a 2.5 per cent reduction in volume. ... The solubility of salt does not change much with temperature, so there is little profit in using hot water.

Answer:

1. NaCl .

Explanation:

Hello there!

In this case, it is necessary to keep in mind that just ionic compounds are able to conduct electricity and therefore, the more ionic the compound is, the more electricity it conducts. In such a way, we may be able to predict how ionic these compounds are, considering that the electronegativity increases from bottom to top and from left to right.

1. NaCl: this is the most ionic compound since it is at the leftmost group and bonded with chlorine, so this is the most conductive one.

2. Mg(CIO3)2: Mg is bonded to O, not to Cl, which makes the compound ionic but not as ionic as NaCl.

3. NiCl: Ni is more electronegative than Na and Mg, so even when this is ionic, it is not as ionic as NaCl.

4. CaCl2: This is similar to NaCl but since Ca is in group 2A, it is more electronegative than Na, which makes CaCl2 conductive but not as much as NaCl.

Best regards!

Answer:

b because the detective ate coffee all day

Answer:

True

Explanation:

Water vapor is totally invisible.

Without it, there would be no clouds or rain or snow, since all of these require water vapor in order to form. All of the water vapor that evaporates from the surface of the Earth eventually returns as precipitation - rain or snow.

Helped by the One & Only #QUEEN aka #DRIPPQUEENMO

Hoped this helped! :)

Answer:

see explanation

Explanation:

HNO₂ ⇄ H⁺ + NO₂⁻

Ka = [H⁺][NO₂⁻]/[HNO₂]

Answer:

No

Explanation:

Answer: smallest whole numbers are 2, 7, 4 and 6

Explanation: C2H6 + 3.5 O2. ⇒ 2. CO2 + 3 H2O

Answer:

Option 2: 6KCl + Ca₃(PO₄)₂

Explanation:

K₃PO₄ + CaCl₂ → Ca₃(PO₄)₂ + KCl

Balancing the equation,

2K₃PO₄ + 3CaCl₂ → Ca₃(PO₄)₂ + 6KCl

∴ the correct formula and coefficients of the products in the equation are,

6KCl + Ca₃(PO₄)₂

Answer:

ionic substances because they contain charged particles

Answer:

Plants add water to the atmosphere

Explanation:

Answer:

The new volume will be 9.24 mL.

Explanation:

Charles's law determines that for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases.

So, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:

[tex]\frac{V}{T} =k[/tex]

When studying an initial state 1 and a final state 2, it is satisfied:

[tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]

In this case:

Replacing:

[tex]\frac{8.70 mL}{318.2 K} =\frac{V2}{337.8 K}[/tex]

Solving:

[tex]V2=337.8K*\frac{8.70 mL}{318.2 K}[/tex]

V2= 9.24 mL

The new volume will be 9.24 mL.

Based on how to wrire chemical formulae, the formula for chlorine monobromide is BrCl.

Chlorine monobromide is a covalent compound formed from the covalent combination of chlorine and bromine.

The covalent bond is formed from the sharing of electrons between atoms chlorine and bromine.

Br2 + Cl2 ---> 2 BrCl

Tye formula of chlorinr monobromide is BrCl.

It is also known as bromine monochloride.

Therefore, the formula for chlorine monobromide is BrCl.

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Answer:

pH = 2.21

Explanation:

Hello there!

In this case, according to the reaction between NaF and HCl as the latter is added to the buffer:

[tex]NaF+HCl\rightarrow NaCl+HF[/tex]

It is possible for us to see how more HF is formed as HCl is added and therefore, the capacity of this HF/NaF-buffer is diminished as it turns acid. Therefore, it turns out feasible for us to calculate the consumed moles of NaF and the produced moles of HF due to the change in moles induced by HCl:

[tex]n_{HF}^{new}=0.300mol+0.150mol=0.450mol\\\\n_{NaF}^{new}=0.200mol-0.150mol=0.050mol[/tex]

Next, we calculate the resulting concentrations to further apply the Henderson-Hasselbach equation:

[tex][HF]=\frac{0.450mol}{1.0L} =0.450M[/tex]

[tex][NaF]=\frac{0.050mol}{1.0L} =0.050M[/tex]

Now, calculated the pKa of HF:

[tex]pKa=-log(6.8x10^{-4})=3.17[/tex]

We can proceed to the HH equation:

[tex]pH=pKa+log(\frac{[NaF]}{[HF]} )\\\\pH=3.17+log(\frac{0.05M}{0.45M} )\\\\pH=2.21[/tex]

Best regards!

pH is the measure of the hydrogen or hydronium ion concentration in an aqueous solution. The pH of the buffer made with HF and NaF is 2.21.

pH is the measure of the acidic or the basic content in a solution that can be given by the hydrogen or the hydroxide concentration.

The reaction can be shown as,

[tex]\rm NaF + HCl \rightarrow NaCl + HF[/tex]

New moles of HF is 0.300 + 0.150 = 0.450 moles and new moles of NaF is 0.200 - 0.150 = 0.050 moles.

The concentration is calculated by the Henderson-Hasselbach equation:

[tex]\rm [HF] = \dfrac{0.450 \;\rm mol}{1.0 \;\rm L} = 0.450 \;\rm M[/tex]

And,

[tex]\rm [NaF] = \dfrac{0.050\;\rm mol}{1.0 \;\rm L} = 0.050\;\rm M[/tex]

pKa of hydrogen fluoride is calculated as:

[tex]\rm pKa = - log (6.8 \times 10^{-4}) = 3.17[/tex]

The pH from the pKa can be calculated as:

[tex]\begin{aligned}\rm pH &=\rm pKa + log (\dfrac{[NaF]}{[HF]})\\\\&= 3.17 + \rm log (\dfrac{0.05}{0.45})\\\\&= 2.21\end{aligned}[/tex]

Therefore, the pH is 2.21.

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Answer:

1 L of O2 reacts with 2 L of SO2.

Explanation:

From the balanced equation, 1 mol of oxygen

reacts with 2 mol sulfur dioxide.

Answer:

check below

Explanation:

c) Concentrated sulphuric acid is used a drying agent.

d) (use any one of them) Concentrated phosphoric acid, hot aluminium oxide, calcium chloride , anhydrous calcium sulphate

Answer:

12c) it is used as a drying agent

d) anhydrous calcium chloride

calcium oxide can also be used as a drying agent

Explanation:

there is what i got hope it helps. ❤❤❤❤❤

Answer:

Aluminum sulfate with barium nitrate to produce burin and aluminum nitrate

Aluminium hydroxide and barium nitrate are produced as a result of the chemical reaction between barium and aluminium nitrate. The reaction's balanced equation is as follows: [tex]2 Al + 3 Ba (NO_3)_3 \rightarrow 3 Ba(NO_3)_2 + 2 Al(OH)_3[/tex]

Chemical reactions are essential natural processes that take place and are in charge of the innumerable alterations and transformations we experience every day. They include the forming and breaking of chemical bonds between atoms, which causes the atoms to be rearranged to produce new compounds with various properties. The concepts of mass and energy conservation control chemical processes. The idea of balanced chemical equations came about because the total number of atoms of each element involved in a reaction stays constant both before and after the reaction. Aluminium hydroxide and barium nitrate are produced as a result of the chemical reaction between barium and aluminium nitrate. The reaction's balanced equation is as follows: [tex]2 Al + 3 Ba (NO_3)_3 \rightarrow 3 Ba(NO_3)_2 + 2 Al(OH)_3[/tex]

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Answer:

The energy of the wave particle is 3.058 x 10⁻²³ J.

Explanation:

Given;

wavelength of the wave particle, λ = 6.5 x 10⁶ nm = (6.5 x 10⁶) x 10⁻⁹ m

The energy of the wave particle is calculated as;

[tex]E = hf\\\\E = \frac{hc}{\lambda}[/tex]

where;

h is Planck's constant = 6.626 x 10⁻³⁴ J/Hz

c is speed of light = 3 x 10⁸ m/s

[tex]E = \frac{(6.626 \times 10^{-34})(3\times 10^8)}{6.5 \times 10^6 \times 10^{-9}} \\\\E = 3.058 \times 10^{-23} \ J[/tex]

Therefore, the energy of the wave particle is 3.058 x 10⁻²³ J.

Answer:

please follow me

Explanation:

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The water is formed from oxygen gas and...hydrogen gas, I'm assuming? It would have been nice for the question to have been a bit more explicit (not blaming you, of course).

Assuming that's the case, our chemical reaction would be:

2H₂(g) + O₂(g) → 2H₂O(l).

We are told that 1 mol of a gas has a volume of 24.0 dm³ at RTP. We can use this relation to determine the number of moles of O₂ gas that reacts given its initial volume, 33.5 dm³.

33.5 dm³ O₂(g)/24.0 dm³/mol = 1.396 mol O₂(g).

Since we are not given any information about H₂(g), or any other reactant for that matter, I am assuming that the O₂(g) is the limiting reactant. According to the equation, the stoichiometric ratio between O₂ and H₂O is 1:2. That is, for every one mole of O₂ that is consumed, two moles of H₂O are formed (i.e., the number of moles of H₂O formed is double the number moles of O₂).

Since 1.396 moles of O₂ reacts, 2(1.396) = 2.792 moles of H₂O are produced. To convert moles of water to grams, we multiply the number of moles of H₂O by the molar mass of H₂O:

(2.792 moles H₂O)(18.015 g/mol) = 50.3 g H₂O.

So, approximately 50.3 grams of water are formed from 33.5 dm³ of oxygen gas at RTP.

Answer:

Nitric Acid

Explanation:

Also known as aqua Fortis and spirt of niter

Hope it helps

Answer:

Nitric Acid

Explanation:

"Nitric acid (HNO3), also known as aqua fortis and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68% in water."

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Answer:

2 C3H6 + 9 O2  6 H2O + 6 CO2

Theo. yield is 440.0 g CO2, % yield = 45.45% Explanation: hope it helps here for ur service

439.16 g of carbon dioxide is produced by complete combustion of 140 g of propene. The percent yield is 45.54%.

Combustion is defined as a high temperature exothermic reaction between a fuel which acts as a reductant and an oxidant which is usually atmospheric oxygen.It does not result in fire as the flame is visible only when substance which undergoes combustion vaporizes.

For combustion reactions to take place stoichiometry is followed according to which mass of reactants or products obtained or required is calculated.

2 C₃H₆ + 9 O₂  [tex]\rightarrow[/tex] 6 CO₂ + 6 H₂O

Here 2 molecules of propene react to give 6 molecules of carbon dioxide.

∴ for 140 grams of propene 140×264/84.16=439.16 g of molecules of CO₂ are produced.

Percent yield is calculated by dividing observed yield by theoretical yield which gives 45.54% according to this example.

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