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Real gases are those that A 2.00-L glass soda bottle filled only with air is tig

ID: 932289 • Letter: R

Question

Real gases are those that A 2.00-L glass soda bottle filled only with air is tightly capped at 18 degree C and 718.0 mmHg. If the bottle is placed in water at 71 degree C, what is the pressure in the bottle? An unknown gaseous hydrocarbon contains 85.63% C. Its density is 1.524 g/L at 0.665 atm and 373 K. What is the molecular formula of the gas? Carbon monoxide reacts with oxygen to form carbon dioxide. In a 1.00 L flask, 4.30 atm of CO reacts with 2.50 atm of O_2. Assuming that the temperature remains constant, what is the final pressure in the flask? Equal volumes of propane. C_3H_3,. and carbon monoxide. CO, at the same temperature and pressure have the same The density of a gas is 3.48 g/L at STP. What is its molar mass?

Explanation / Answer

21) we know that

PV = nRT

here volume of bottle remains same

so

P / T = constant

at two conditions

P1/T1 = P2 / T2

so

718 / 291 = P2 / 344

P2 = 849 mm Hg

so

the answer is b) 849 mm Hg


23)

PV = nRT

PV = mRT / M

PM = ( m / V) RT

PM = dRT

0.665 x M = 1.524 x 0.0821 x 373

M = 70

so

the molar mass is 70

let hydrocarbon be CaHb

then

12a + b = 70

now

12a / 70 = 0.8563

a = 5

so

b = 10

so

C5H10

the answer is d) C5H10

25)

2C0 + 02 --> 2 C02

for C0

PV = nRT

4.3 x 1 = n x 0.0821 x 298

n = 0.1757

moles of C0 = 0.1757

moles of 02 = 2.5 / 0.0821 x 298

moles of 02 = 0.1022

now

2C0 + 02 --> 2 C02

moles of 02 reacted = 0.5 x moles of C0

moles of 02 reacted = 0.08785

moles of 02 remaining = 0.1022 - 0.08785 = 0.01435

moles of C0 remaining = 0

moles of C02 formed = moles of C0 reacted = 0.1757

now

finally

total moles = 0.1757 + 0.01435

total moles = 0.19005

now

PV = nRT

P x 1 = 0.19005 x 0.0821 x 298

P = 4.65

so

final pressure is 4.65 atm

answer is d) 4.65 atm

27)

PV = nRT

given

volume are same , pressure and temp are also same

so

both will same moles

so both will have same molecules

so

e) number of molecules


28)

STP conditions are

P = 1 atm

T = 273 K

so

PM = dRT

1 x M = 3.48 x 0.0821 x 273

M = 78

so

the molar mass of the gas is 78 g / mol