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3 years ago

When do you start to pair up the electron dots?

Chemistry

1 answer:

k0ka [10]3 years ago

3 0

When covalent bonding is being used

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Kinsey eats a banana and then goes to basketball practice. She runs down the court and passes the ball. She is changing ________

WITCHER [35]

Answer:The Answer is D

Explanation:

3 0

3 years ago

A student hypothesized that the green color of plant leaves is related to exposure to sunlight and tested this hypothesis by pla

kkurt [141]

The hypothesis is that
the green coloration of plants is related to sunlight exposure of leaves
The hypothesis is tested by keeping a dark green plant inside a dark closet
The result is that the green coloration faded
The conclusion must be that exposure to sunlight affects the green color of the plants

8 0

4 years ago

Read 2 more answers

An unknown acid solution has PH 3.4. 66% of the acid is ionized. Whats the pka?

juin [17]

Answer:

$pKa=3.58$

Explanation:

Hello,

In this case, since the pH defines the concentration of hydrogen:

$pH=-log([H^+])$

$[H^+]=10^{-pH}=10^{-3.4}=3.98x10^{-4}$

And the percent ionization is:

$\% \ ionization=\frac{[H^+]}{[HA]}*100\%$

We compute the concentration of the acid, HA:

$[HA]=\frac{[H^+]}{\% \ ionization}*100\%=\frac{3.98x10^{-4}}{66\%} *100\%\\\\$

$[HA]=6.03x10^{-4}$

Thus, the Ka is:

$Ka=\frac{[H^+][A^-]}{[HA]}=\frac{3.98x10^{-4}*3.98x10^{-4}}{6.03x10^{-4}}\\ \\Ka=2.63x10^{-4}$

So the pKa is:

$pKa=-log(Ka)=-log(2.63x10^{-4})\\\\pKa=3.58$

Regards.

5 0

3 years ago

To prepare an acetic acid/acetate buffer, a technician mixes 30.6 mL of 0.0880 acetic acid and 21.6 mL of 0.110 sodium acetate i

enyata [817]

Answer: There are 0.00269 moles of acetic acid in buffer.

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution in ml}}$ .....(1)

Molarity of acetic acid solution = 0.0880 M

Volume of solution = 30.6 mL

Putting values in equation 1, we get:

$0.0880M=\frac{\text{Moles of acetic acid}\times 1000}{30.6ml}\\\\\text{Moles of acetic acid}=\frac{0.0880\times 30.6}{1000}=0.00269mol$

Thus there are 0.00269 moles of acetic acid in buffer.

8 0

3 years ago

What were the four elements that ancient Greeks believed to exist

ruslelena [56]

Answer:

The ancient Greeks believed in the four elements of air, earth, fire, and water. The Greek philosopher Empedocles is known for originating the theory of these classic four elements being the basis of all things.

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3 years ago