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2 years ago

Lunar Eclipse. Choose ALL that apply

Chemistry

2 answers:

antoniya [11.8K]2 years ago

6 0

Answer:

b and a i jus did it

Explanation: none

Ronch [10]2 years ago

5 0

Answer:

the answer to 1 is all the answers

the 2 one is Moon moves between the sun and Earth and The moon blocks out the light of the sun and casts a shadow onto the Earth

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An analytical chemist is titrating of a solution of propionic acid with a solution of 224.9 ml of a 0.6100M solution of propioni

Svetllana [295]

Answer: The pH of acid solution is 4.58

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)

For KOH:

Molarity of KOH solution = 1.1000 M

Volume of solution = 41.04 mL

Putting values in equation 1, we get:

$1.1000M=\frac{\text{Moles of KOH}\times 1000}{41.04}\\\\\text{Moles of KOH}=\frac{1.1000\times 41.04}{1000}=0.04514mol$

For propanoic acid:

Molarity of propanoic acid solution = 0.6100 M

Volume of solution = 224.9 mL

Putting values in equation 1, we get:

$0.6100M=\frac{\text{Moles of propanoic acid}\times 1000}{224.9}\\\\\text{Moles of propanoic acid}=\frac{0.6100\times 224.9}{1000}=0.1372mol$

The chemical reaction for propanoic acid and KOH follows the equation:

$C_2H_5COOH+KOH\rightarrow C_2H_5COOK+H_2O$

Initial: 0.1372 0.04514

Final: 0.09206 - 0.04514

Total volume of solution = [224.9 + 41.04] mL = 265.94 mL = 0.26594 L (Conversion factor: 1 L = 1000 mL)

To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:

$pH=pK_a+\log(\frac{[\text{salt}]}{[acid]})$

$pH=pK_a+\log(\frac{[C_2H_5COOK]}{[C_2H_5COOH]})$

We are given:

$pK_a$ = negative logarithm of acid dissociation constant of propanoic acid = 4.89

$[C_2H_5COOK]=\frac{0.04514}{0.26594}$

$[C_2H_5COOH]=\frac{0.09206}{0.26594}$

pH = ?

Putting values in above equation, we get:

$pH=4.89+\log(\frac{(0.04514/0.26594)}{(0.09206/0.26594)})\\\\pH=4.58$

Hence, the pH of acid solution is 4.58

7 0

3 years ago

Magnesium reacts with a certain element to form a compound with the general formula MgX. What would the most likely formula be f

ziro4ka [17]

Answer:K2X

Explanation: Valency can be defined as the combining power of an element. It is the valency that dictates the value an element will have when writing a chemical formula for its compound.

MgX is a compound of magnesium and an element X. The valency of magnesium in most of its compound is +2. Now for the 2 to have been absent in the chemical formula, this shows that the element X itself have a valency if -2 for the valencies of both to have canceled out.

Now considering the element potassium, it is an alkaline metal belonging to group 1 of the periodic table. Hence, it is expected that it has a valency of +1

Forming a compound with element X means there would be an exchange of valencies between the two. We have established that x has a valency of -2. The formula of the compound thus formed by exchanging the valencies of both element would be K2X

7 0

2 years ago

Read 2 more answers

Predict whether each of the following is soluble in water or not.

wlad13 [49]

Answer:

The soluble in water are a and b. c is not soluble in water

Explanation:

The water solubility of a compound, it depends its polarity (. KHSO4 has several polar molecules, actually it has ions charged positively like K and H, and charged negatively like sulfate (SO4-2). When it happens, molecules can do hydrogen bridges with water. It is because of above, KHSO4 can be used in wine making. Something similar happens with propylen glycol but in this case the polar part is OH- ions. Benzene has not polar parts. It is totally apolar compound.

I hope my answer helps you

4 0

3 years ago

Identify how many of the original parent nuclei remain after three half-lives

Nutka1998 [239]

Answer:

yes

Explanation:

i did the test

3 0

2 years ago

A balloon filled with helium occupies 20.0 l at 1.50 atm and 25.0◦c. How many moles of helium will there be in the balloon at st

satela [25.4K]

Answer:

There will be 1.23 moles of helium in the balloon at STP

Explanation:

1) Initial conditions of the helium gas:

V = 20.0 liter
p = 1.50 atm
T = 25.0 °C = 25.0 + 273.15 K = 298.15 K

2) Ideal gas equation:

pV = n RT
p, V, and T are given above
R is the Universal constant = 0.0821 atm-liter / ( K - mol)
n is the unknown number of moles

3) Solve for n:

n = pV / (RT) =

n = 1.50 atm × 20.0 liter / (0.0821 atm-liter /k -mol ×298.15K)

n = 1.23 mol

4) At STP:

STP stands for standard pressure and temperature.

The amount (number of moles) of the gas will not change because the change of pressure and temperature, so the number of moles reamain the same: 1.23 mol.

8 0

2 years ago