For each of the molecules determine if they have the following center of symmetry, the axis of symmetry and plane of symmetry

a gas sample occupies a volume of 140 mL at a temperature of 296 K and a pressure of 98.2kPa. how many moles of gas are there? s

Tamiku [17]

Answer:

0.00559 mol

Explanation:

The following data were obtained from the question:

V = 140mL = 0.14L

T = 296K

P = 98.2kPa = 98200Pa

Recall: 101325Pa = 1atm

98200Pa = 98200/101325 = 0.97atm

R = 0.082atm.L/Kmol

n =?

The number of mole (n) can be obtained as follows:

PV = nRT

n = PV /RT

n = (0.97x0.14)/(0.082x296)

n = 0.00559 mol

Therefore, the number of mole of the gas present is 0.00559 mol

4 0

3 years ago

How would you prepare 500 ml of the following solutions : Sodium succinate buffer (0.1 mol/dm3 pH 5.64)

Nana76 [90]

Answer:

8.10g of sodium succinate must be added and 247mL of 0.1M HCl adding enough water until make 500mL

Explanation:

Succinic acid has a pKa₂ of 5.63

To solve this question we must find the amount of sodium succinate and 0.1M HCl that we have to add using H-H equation:

pH = pKa + log [A-] / [HA]

5.64 = 5.63 + log [Na₂Succ.] / [HSucc⁺]

0.01 = log [Na₂Succ.] / [HSucc⁺]

1.0233 = [Na₂Succ.] / [HSucc⁺] (1)

As:

0.1M = [Na₂Succ.] + [HSucc⁺] (2)

Replacing (2) in (1):

1.0233 = 0.1M - [HSucc⁺] / [HSucc⁺]

1.0233[HSucc⁺] = 0.1M - [HSucc⁺]

2.033[HSucc⁺] = 0.1M

[HSucc⁺] = 0.0494M

[Na₂Succ] = 0.0506M

Both [Na₂Succ⁺] and [HSucc⁺] ions comes from the same sodium succinate we have to find the moles of sodium succinate in 500mL of 0.1M. Then, based on the reaction:

Na₂Succ + HCl → HSucc⁺ + Cl⁻

The moles of HCl added = Moles HSucc⁺ we need:

Moles Na₂Succ:

0.500L * (0.1mol/L) = 0.0500 moles

Mass -Molar mass sodium succinate: 162.05g/mol-:

0.0500mol * (162.05g/mol) = 8.10g of sodium succinate must be added

Moles HCl:

0.0494M * 0.500L = 0.0247 moles HCl * (1L / 0.1mol) = 0.247L =

And 247mL of 0.1M HCl adding enough water until make 500mL

7 0

3 years ago

How are transuranium elements made?

g100num [7]

Explanation:

The transuranium elements are produced by the capture of neutrons

Hope it will help you

4 0

3 years ago

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Use the following half-reactions to write three spontaneous reactions, calculate E°cell for each reaction, and rank the oxidizin

Ainat [17]

Answer:

See explaination

Explanation:

1)

we know that

half cell with higher reduction potential is cathode

so

cathode :

N20 + 2H+ + 2e- ---> N2 + H20

anode :

Cr(s) ---> Cr+3 + 3e-

so

overall reaction is

3 N20 + 6H+ + 2 Cr ---> 3N2 + 3H20 + 2Cr+3

now

Eo cell = Eo cathode - Eo anode

so

EO cell = 1.77 + 0.74

Eo cell = 2.51 V

now

in this case

oxidizing agents are N20 and Cr+3

reducing agents are Cr and N2

higher the reduction potential , stronger the oxidizing agent

lower the reduction potential , stronger the reducing agent

so

oxidzing agents

N20 > Cr+3

reducing agents

Cr > N2

2)

cathode :

Au+ + e- --> Au

anode :

Cr ---> Cr+3 + 3e-

overall reaction

3Au+ + Cr ---> 3Au + Cr+3

Eo cell = 1.69 + 0.74

Eo cell = 2.43

now

oxidizing agents :

Au+ > Cr+3

reducing agents :

Cr > Au

3)

cathode :

N20 + 2H+ + 2e- ---> N2 + H20

andoe :

Au ---> Au+ + e-

overall

2 Au + N20 + 2H+ --> 2 Au+ + N2 + H20

Eo cell = 1.77 - 1.69

Eo cell = 0.08

oxidizing agents

N20 > Au+

reducing agents

Au > N2

8 0

3 years ago

The images show two unrelated events occurring at separate times.

trapecia [35]

Event 1 is an example of a chemical reaction.

Explanation:

Whenever if two solutions are mixed, then if there is any color change, or evolution of any vapors, bubbles or gas formation or if there is any formation of a color or white precipitate confirms that the occurrence of a chemical reaction.

If nothing happens said above then it is said that there is no chemical reaction occurs.

Here in the event 1 a clear liquid in one beaker poured into clear liquid in beaker 2 then there is a formation of orange liquid, which means there is a formation of a new colored liquid confirms that the chemical reaction occurred.

4 0

3 years ago

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