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2 years ago

The mass number of an atom is determined by ___.

Chemistry

1 answer:

Ronch [10]2 years ago

4 0

Answer:

Explanation:

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There is a mixture of three gases. We know the total pressure is 2.50 atmosphere and the pressure of the oxygen and the nitrogen

Viktor [21]

Answer:

1.14 atm and 1.139 mol

Explanation:

The total pressure of the container is equal to the sum of the partial pressure of the three gasses:

P = Poxygen + Pnitrogen + Pcarbon dioxide

2.50 atm = 0.52 + 0.84 + Pcarbon dioxide

Now we solve for the pressure of carbon dioxide:

Pcarbon dioxide = 1.14 atm

To calculate the number of CO₂ moles we use PV=nRT:

P = 1.14 atm

V = 25.0 L

n = ?

R = 0.082 atm·L·mol⁻¹·K⁻¹

T = 32 °C ⇒ 32 + 273.16 = 305.16 K

1.14 atm * 25.0 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 305.16 K

n = 1.139 mol

5 0

3 years ago

Using standard heats of formation, calculate the standard enthalpy change for the following reaction. 2H2S(g) 3O2(g)2H2O(l) 2SO2

Marizza181 [45]

Answer:

$\Delta _rH=-1124.14kJ/mol$

Explanation:

Hello!

In this case, since the standard enthalpy change for a chemical reaction is stood for the enthalpy of reaction, for the given reaction:

$2H_2S(g) +3O_2(g)\rightarrow 2H_2O(l) +2SO_2(g)$

We set up the enthalpy of reaction considering the enthalpy of formation of each species in the reaction at the specified phase and the stoichiometric coefficient:

$\Delta _rH=2\Delta _fH_{H_2O,liq}+2\Delta _fH_{SO_2,gas}-2\Delta _fH_{H_2S,gas}-3\Delta _fH_{O_2,gas}$

In such a way, by using the NIST database, we find that:

$\Delta _fH_{H_2O, liq}=-285.83kJ/mol\\\\\Delta _fH_{SO_2, gas}=-296.84kJ/mol\\\\\Delta _fH_{O_2,gas}=0kJ/mol\\\\\Delta _fH_{H_2S,gas}=-20.50kJ/mol$

Thus, we plug in the enthalpies of formation to obtain:

$\Delta _rH=2(-285.73kJ/mol)+2(-296.84kJ/mol)-2(-20.50kJ/mol)-3(0kJ/mol)\\\\\Delta _rH=-1124.14kJ/mol$

Best regards!

8 0

2 years ago

What is one wavelength?

Dmitry_Shevchenko [17]

Answer:

It is the distance between two compressions or two rarefactions.

Explanation:

7 0

3 years ago

On which energy level are the valence electrons for calcium (Ca) ?

zhannawk [14.2K]

The fourth (last) one in 2-8-8-2.

7 0

2 years ago

In which environment would primary succession occur?

taurus [48]

Answer:

an area of exposed rock after a glacier melts away

Explanation:

i took the test

3 0

3 years ago

Read 2 more answers