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4 years ago

Calculate the pOH of a 0.410 M Ba(OH)2 solution.

1 answer:

4 0

The dissociation of this basic compound is: $Ba(OH)_2\ \to\ Ba^{2+} + 2OH^-$

There will be the double of $OH^-$ ions than molecules of $Ba(OH)_2$ , therefore, the concentration of $OH^-$ at the end will be 0.820 M.

$pOH = -log\ [OH^-] = - log (0.820) = \bf 0.09$

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1. The Yerkes-Dodson Law says

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Answer:

The Yerkes-Dodson Law suggests that there is a relationship between performance and arousal. Increased arousal can help improve performance, but only up to a certain point.

Explanation:

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3 years ago

Which of the following objects would have the most inertia?

ankoles [38]

I believe it is A or D

3 0

4 years ago

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What is the wavelength of one ultraviolet photon if it’s frequency is 1.50 x 10^15 s^-1

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C=λν ==> λ=c/ν

λ= 3x10^8 m/s / 1.50 x 10^15 s^-1
λ= 2 x 10^-7 m
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3 years ago

Considering that the mantle is 44.8% oxygen and 21.5% silicon by mass, calculate the mole ratio of oxygen atoms to silicon atoms

horrorfan [7]

The mantle has a mass of around $4.278 X 10 ^2^4 kg$ that is around 68.4% of earth's mass.

So to calculate moles we need to first find out the mass of oxygen and silicon present in mantle. It is given that oxygen is 44.8% by mass in mantle and 21.5% by mass in mantle, therefore to calculate its mass, we need to use $\text{mass percentage }=\frac{\text{mole of solute}}{\text{mass of solution}}\times100$

Now, to calculate mass percentage of oxygen

$44.8 =\frac{x}{4.278X10^2^4kg}\times100$

$x= 191.65\times10^2^2kg$

Similarly the mass of silicon can be calculated

$21.5 =\frac{x}{4.278X10^2^4kg}\times100$

$x=91.977\times10^2^2kg$

Now, the moles of any substance is calculated by

$\text{moles}= \frac{\text{given mass}}{\text{molar mass}}$

$\text{moles of oxygen}= \frac{191.65\times10^2^2kg}{2.6566962\times10^-^2^6kg}$

where, mass of oxygen in kilograms is $2.6566962\times10^-^2^6kg$

So, $\text{moles of oxygen}=72.1384\times10^4^8\text{moles of O}$

Similarly $\text{moles of silicon}= \frac{91.977\times10^2^2kg}{4.663\times10^-^2^6kg}$

$\text{moles of silicon}=19.724\times10^4^8\text{moles of Si}$

Now, to calculate mole ratio we need to divide every moles to the lowest calculated mole that is the moles of Si and round it off to the nearest whole number.

$\text{mole ratio of oxygen}= \frac{72.138\times10^4^8kg}{19.724\times10^4^8kg}$

$=3.65\approx 4$

$\text{mole ratio of Silicon}=\frac{19.724\times10^4^8}{19.724\times10^4^8}$

$=1$

$\text{Mole ratio of Oxygen : Mole ratio of Silicon} = 4:1$

6 0

4 years ago

Read 2 more answers

The electron pair in a C-F bond could be considered Question 3 options: closer to C because carbon has a larger radius and thus

Leokris [45]

Answer:

closer to F because fluorine has a higher electronegativity than carbon

Explanation:

Electronegativity refers to the ability of an atom in a bonding situation to draw the shared electrons of the bond closer to itself.

Electronegativity increases across the period and decreases down the group. A highly electronegative atom draws the shared electron pair of a bond towards itself.

When two atoms are bonded together, the electron pair is always drawn closer to the atom that has a higher electronegativity.

Hence, the electron pair in a C-F bond could be considered closer to F because fluorine has a higher electronegativity than carbon.

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3 years ago