Class if you are in-person). You will be allowed two

Sedbober [7]

This chemical reaction can also be written as

2C2H6+7O2-->4CO2+6H2O

This is a chemical reaction because reactants are converted into products. This is the combustion of ethane where ethane and oxygen have been converted into carbon dioxide and water

8 0

3 years ago

A cylinder contains 250 g of Helium at 200 K. The external pressure is constant at 1 atm. The temperature of the system is raise

Black_prince [1.1K]

Answer:

There is 96200 J or 96 kJ of heat released.

Explanation:

Step 1: Data given

Mass of helium = 250 grams

Temperature = 200 K

Temperature is raised by 74 K

The heat capacity of helium = 20.8 J/mol*K

Molecular weight for helium = 4 g/mol

Step 2: Calculate moles of Helium

Moles of Helium = mass of Helium / molar mass of helium

Moles of helium = 250 grams / 4g/mol

Moles of helium = 62.5 moles

Step 3: Calculate heat

Q = n*c*ΔT or

⇒ with Q = the heat released in Joule

⇒ with n = moles of helium = 62.5 moles

⇒ with c = the heat capacity of helium = 20.8 J/mol*K

⇒ with ΔT = the change in temperature = T2 - T1 = 74 K

Q = 62.5 mol * 20.8 J/mol*K * 74 K

Q = 96200 J = 96 kJ

Since the temperature is raised, this is an exothermic reaction. The heat is released.

There is 96200 J or 96 kJ of heat released.

8 0

3 years ago

2.714 mole of helium has a mass of ______ grams. (Enter just the number for this one.)

kifflom [539]

Hello!

To find the mass of helium, we need to multiply the total moles by the mass of helium. We are given 2.714 moles of helium, and the mass of helium is about 4.00 grams. Now, we multiply the two values together to get the grams.

2.714 moles x 4.00 grams = 10.856 grams

According to the number of significant figures, 2.714 moles of helium has a mass of 10.9 grams (exact value: 10.856 grams).

6 0

3 years ago

A sample of methane gas, CH4, occupies 3.25 L at temperature of 19.0 o C. If the pressure is held constant, what will be the tem

Artemon [7]

Answer:

625.46 °C

Explanation:

We'll begin by converting 19 °C to Kelvin temperature. This can be obtained as follow:

T(K) = T(°C) + 273

T(°C) = 19 °C

T(K) = 19 °C + 273

T(K) = 292 K

Next, we shall determine the Final temperature. This can be obtained as follow:

Initial volume (V₁) = 3.25 L

Initial temperature (T₁) = 292 K

Final volume (V₂) = 10 L

Final temperature (T₂) =?

V₁/T₁ = V₂/T₂

3.25 / 292 = 10 / T₂

Cross multiply

3.25 × T₂ = 292 × 10

3.25 × T₂ = 2920

Divide both side by 3.25

T₂ = 2920 / 3.25

T₂ = 898.46 K

Finally, we shall convert 898.46 K to celsius temperature. This can be obtained as follow:

T(°C) = T(K) – 273

T(K) = 898.46 K

T(°C) = 898.46 – 273

T(°C) = 625.46 °C

Therefore the final temperature of the gas is 625.46 °C

4 0

3 years ago

At a certain temperature the vapor pressure of pure chloroform (CHCl3) is measured to be 91. torr. Suppose a solution is prepare

OleMash [197]

Answer:

$P_{CCl_4}=52.43torr$

Explanation:

Hello there!

In this case, sine the solution of this problem require the application of the Raoult's law, assuming heptane is a nonvolatile solute, so we can write:

$P_{CCl_4}=x_{CCl_4}P_{CCl_4}^{vap}$

Thus, we first calculate the mole fraction of chloroform, by using the given masses and molar masses as shown below:

$x_{CCl_4}=\frac{140/153.81}{140/153.81+67.1/100.21}=0.576$

Therefore, the partial pressure of chloroform turns out to be:

$P_{CCl_4}=0.576*91torr\\\\P_{CCl_4}=52.43torr$

Regards!

3 0

3 years ago