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3 years ago

HELP! ME! PLEASE!

Chemistry

1 answer:

tankabanditka [31]3 years ago

7 0

Answer:

Explanation:

Magnetism or magnetic field lines move through just about anything. The earth somehow creates a magnet near it"s center and these magnetic field lines move through the lava, rock, and soil of the earth to control a compass on the surface. So moving through a piece of cardboard is no problem for magnetism.

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Express in scientific notation. Choose the answer with the proper number of significant figures.

bazaltina [42]

Answer:

4.5 times 10 = 45

Explanation:

"Non-zero digits are always significant. Any zeros between two significant digits are significant. A final zero or trailing zeros in the decimal portion ONLY are significant."

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3 years ago

Which of the following is not a concern regarding the use of corn as biofuel

Lady_Fox [76]

The color of corn is different than the color of gasoline or coal.

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4 years ago

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Which of the following conditions indicate a basic solution at 25°C?

gladu [14]

Answer:

B. , C. and D.

Explanation:

pH is defined as the negative logarithm of the concentration of hydrogen ions.

Thus,

pH = - log [H⁺]

pH scale generally runs from 1 to 14 where pH = 7 represents neutral medium, pH < 7 represents acidic medium and pH > 7 represents basic medium.

Also, pH + pOH = 14

(a) So, pOH = 11.21

pH = 14 - 11.21 = 2.79

The solution is acidic.

(b) pH = 9.42

The solution is basic.

c. [OH⁻] > [H⁺]

More concentration of hydroxide ions leads to basic solution.

d. [OH⁻]> 1.0 x 10⁻⁷ M

1.0 x 10⁻⁷ M leads to neutral solution and hydroxide ions concentration greater than this yields to basic solution.

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4 years ago

Fill in the blank...<br> Each element is made up of only one kind of ________

strojnjashka [21]

Each element is made up of only one kind of atom.

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3 years ago

Calculate E ° for the half‑reaction, AgCl ( s ) + e − − ⇀ ↽ − Ag ( s ) + Cl − ( aq ) given that the solubility product constant

antoniya [11.8K]

Answer: The value of $E^{o}$ for the half-cell reaction is 0.222 V.

Explanation:

Equation for solubility equilibrium is as follows.

$AgCl(s) \rightleftharpoons Ag^{+}(aq) + Cl^{-}(aq)$

Its solubility product will be as follows.

$K_{sp} = [Ag^{+}][Cl^{-}]$

Cell reaction for this equation is as follows.

$Ag(s)| AgCl(s)|Cl^{-}(0.1 M)|| Ag^{+}(1.0 M)| Ag(s)$

Reduction half-reaction: $Ag^{+} + 1e^{-} \rightarrow Ag(s)$ , $E^{o}_{Ag^{+}/Ag} = 0.799 V$

Oxidation half-reaction: $Ag(s) + Cl^{-}(aq) \rightarrow AgCl(s) + 1e^{-}$ , $E^{o}_{AgCl/Ag}$ = ?

Cell reaction: $Ag^{+}(aq) + Cl^{-}(aq) \rightarrow AgCl(s)$

So, for this cell reaction the number of moles of electrons transferred are n = 1.

Solubility product, $K_{sp} = [Ag^{+}][Cl^{-}]$

= $1.77 \times 10^{-10}$

Therefore, according to the Nernst equation

$E_{cell} = E^{o}_{cell} - \frac{0.0592 V}{n} log \frac{[AgCl]}{[Ag^{+}][Cl^{-}]}$

At equilibrium, $E_{cell}$ = 0.00 V

Putting the given values into the above formula as follows.

$E_{cell} = E^{o}_{cell} - \frac{0.0592 V}{n} log \frac{[AgCl]}{[Ag^{+}][Cl^{-}]}$

$0.00 = E^{o}_{cell} - \frac{0.0592 V}{1} log \frac{1}{[Ag^{+}][Cl^{-}]}$

$E^{o}_{cell} = \frac{0.0592}{1} log \frac{1}{K_{sp}}$

= $0.0591 V \times log \frac{1}{1.77 \times 10^{-10}}$

= 0.577 V

Hence, we will calculate the standard cell potential as follows.

$E^{o}_{cell} = E^{o}_{cathode} - E^{o}_{anode}$

$0.577 V = E^{o}_{Ag^{+}/Ag} - E^{o}_{AgCl/Ag}$

$0.577 V = 0.799 V - E^{o}_{AgCl/Ag}$

$E^{o}_{AgCl/Ag}$ = 0.222 V

Thus, we can conclude that value of $E^{o}$ for the half-cell reaction is 0.222 V.

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3 years ago