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3 years ago

What is concentration in science

Chemistry

2 answers:

alexandr1967 [171]3 years ago

7 0

The amount of something that you have in a liquid (most commonly)

snow_tiger [21]3 years ago

6 0

The amount of a substance that you have in units per volume

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What total volume of ozone measured at a pressure of 24.5 mmHg and a temperature of 232 K can be destroyed when all of the chlor

ddd [48]

Answer:

$1.75272\ \text{m}^3$

Explanation:

The breakdown reaction of ozone is as follows

$CF_3Cl + UV \rightarrow CF_3 + Cl$

$Cl + O_3 \rightarrow ClO + O_2$

$O_3 + UV \rightarrow O_2 + O$

$ClO + O \rightarrow Cl + O_2$

It can be seen that 2 moles of ozone is required in the complete cycle

So for 10 cycles, 20 moles of ozone is required

m = Mass of $CF_3Cl$ = 15.5 g

M = Molar mass of $CF_3Cl$ = 104.46 g/mol

P = Pressure = 24.5 mmHg

T = Temperature = 232 K

R = Gas constant = $62.363\ \text{L mmHg/K mol}$

Number of moles is given by

$n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{15.5}{104.46}\\\Rightarrow n=0.1484\ \text{moles}$

$20\ \text{moles} = 20\times 0.1484 = 2.968\ \text{moles}$

From ideal gas law we have

$PV=nRT\\\Rightarrow V=\dfrac{nRT}{P}\\\Rightarrow V=\dfrac{2.968\times 62.363\times 232}{24.5}\\\Rightarrow V=1752.72\ \text{L}=1.75272\ \text{m}^3$

For 20 cycles of the reaction the volume of the ozone is $1.75272\ \text{m}^3$ .

7 0

3 years ago

If 150 g dimethylhydrazine reacts with excess dinitrogen tetroxide and the product gases are collected at 127oC in an evacuated

zhuklara [117]

Answer : The the partial pressure of the nitrogen gas is 0.981 atm.

The total pressure in the tank is 2.94 atm.

Explanation :

The balanced chemical reaction will be:

$(CH_3)_2N_2H_2(l)+2N_4O_4(l)\rightarrow 3N_2(g)+4H_2O(g)+2CO_2(g)$

First we have to calculate the moles of dimethylhydrazine.

Mass of dimethylhydrazine = 150 g

Molar mass of dimethylhydrazine =60.104 g/mole

$\text{Moles of dimethylhydrazine}=\frac{\text{Mass of dimethylhydrazine}}{\text{Molar mass of dimethylhydrazine}}$

$\text{Moles of dimethylhydrazine}=\frac{150g}{60.104g/mole}=2.49mole$

Now we have to calculate the moles of $N_2$ gas.

From the balanced chemical reaction we conclude that,

As, 1 mole of $(CH_3)_2N_2H_2$ react to give 3 moles of $N_2$ gas

So, 2.49 mole of $(CH_3)_2N_2H_2$ react to give $2.49\times 3=7.47$ moles of $N_2$ gas

Now we have to calculate the partial pressure of nitrogen gas.

Using ideal gas equation :

$PV=nRT\\\\P_{N_2}=\frac{nRT}{V}$

where,

P = Pressure of $N_2$ gas = ?

V = Volume of $N_2$ gas = 250 L

n = number of moles $N_2$ gas = 7.47 mole

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of $N_2$ gas = $127^oC=273+127=400K$

Putting values in above equation, we get:

$P_{N_2}=\frac{(7.47mole)\times (0.0821L.atm/mol.K)\times 400K}{250L}=0.981atm$

Thus, the partial pressure of the nitrogen gas is 0.981 atm.

Now we have to calculate the total pressure in the tank.

Formula used :

$P_{N_2}=X_{N_2}\times P_T$

$P_T=\frac{1}{X_{N_2}}\times P_{N_2}$

$P_T=\frac{1}{(\frac{n_{N_2}}{n_T})}\times P_{N_2}$

$P_T=\frac{n_{T}}{n_{N_2}}\times P_{N_2}$

where,

$P_T$ = total pressure = ?

$P_{N_2}$ = partial pressure of nitrogen gas = 0.981 atm

$n_{N_2}$ = moles of nitrogen gas = 3 mole (from the reaction)

$n_{T}$ = total moles of gas = (3+4+2) = 9 mole (from the reaction)

Now put all the given values in the above formula, we get:

$P_T=\frac{9mole}{3mole}\times 0.981atm=2.94atm$

Thus, the total pressure in the tank is 2.94 atm.

8 0

3 years ago

What does " a man's home is his castle " mean

slega [8]

It means that someone's home is more than just a home to someone much more meaningful and precious like a castle

8 0

3 years ago

Determine the expression for the equilibrium constant, KcKcK_c, for the reaction by identifying which terms will be in the numer

Yakvenalex [24]

Answer: Hello your question lacks some details below is the complete question

answer :

Numerator = CH₃OH

Denominator = (CO ) ( H₂)²

Explanation:

CO + 2H₂ ⇄ CH₃OH ( formation of methanol )

hence for the equilibrium constant Kc

Numerator = CH₃OH

Denominator = (CO ) ( H₂)²

<u><em>Placing into the Bin </em></u>

Numerator : CH₃OH

Denominator : (CO ) ( H₂)²

Not Used : ( CO )² , H₂ , ( CH₃OH ) ²

8 0

3 years ago

According to Le Châtelier's principle, how would a change in pressure affect a

katrin2010 [14]

Answer:

Le Châtelier's principle states that when a chemical system at equilibrium is distributed by a change in conditions, the equilibrium position will shift in a direction that tends to counteract the change.

Therefore, when there is a change in pressure, the equilibrium will counteract the change by reducing/increasing the pressure through adjusting the no. of moles of gas.

Note: At constant temperature and volume the pressure of a gas is directly proportional to the number of moles of gas.

For example, when there's an increase in total pressure, the equilibrium position will shift to the side with a smaller no. of moles of gas so as to reduce the pressure.

4 0

3 years ago

What is concentration in science​

What is concentration in science