A chemist weighed out 19.9 g of aluminum. Calculate the number of moles of aluminum she weighed out.

How many moles of a gas would occupy 22.4 Liters at 273 K and 1 atm?

Molodets [167]

Answer:

1 mole of a gas would occupy 22.4 Liters at 273 K and 1 atm

Explanation:

An ideal gas is a set of atoms or molecules that move freely without interactions. The pressure exerted by the gas is due to the collisions of the molecules with the walls of the container. The ideal gas behavior is at low pressures, that is, at the limit of zero density. At high pressures the molecules interact and intermolecular forces cause the gas to deviate from ideality.

An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:

P * V = n * R * T

In this case:

P= 1 atm
V= 22.4 L
n= ?
R= 0.082 $\frac{atm*L}{mol*K}$
T=273 K

Reemplacing:

1 atm* 22.4 L= n* 0.082 $\frac{atm*L}{mol*K}$ *273 K

Solving:

$n=\frac{1 atm* 22.4 L}{0.082 \frac{atm*L}{mol*K} *273 K}$

n= 1 mol

Another way to get the same result is by taking the STP conditions into account.

The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C (or 273 K) are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.

1 mole of a gas would occupy 22.4 Liters at 273 K and 1 atm

4 0

2 years ago

The pyrolysis of ethane proceeds with an activation energy of about 300 kJ/mol. How much faster is the decomposition at 625°C th

Alona [7]

Answer:

The decomposition of ethane is 153.344 times much faster at 625°C than at 525°C.

Explanation:

According to the Arrhenius equation,

$K=A\times e^{\frac{-Ea}{RT}}$

$\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]$

where,

$K_2$ = rate of reaction at $T_2$

$K_1$ = rate of reaction at $T_1$

$Ea$ = activation energy of the reaction

R = gas constant = 8.314 J/K mol

$E_a=300 kJ/mol=300,000 J/mol$

$T_2=625^oC=898.15 K,T_1=525^oC=798.15 K$

$\log (\frac{K_2}{K_1})=\frac{300,000 J/mol}{2.303\times 8.314 J/K mol}[\frac{1}{798.15 K}-\frac{1}{898.15 K}]$

$\log (\frac{K_2}{K_1})=2.185666$

$K_2=153.344\times K_1$

The decomposition of ethane is 153.344 times much faster at 625°C than at 525°C.

4 0

2 years ago

Order the terms according to the path followed by oxygen during cellular respiration.

MArishka [77]

Answer:

Outside air

Nose

Lungs

Bloodstream

Cell

Explanation:

We breathe in oxygen from the outside air in through our nose and it travels to our lungs. Inside our lungs, we have Avioli's that diffuse oxygen into our bloodstream and the bloodstream helps the oxygen travel into our cells.

Hope this helps :)

8 0

2 years ago

An example of a physical property of an element is the element’s ability to(1) react with an acid(2) react with oxygen(3) form a

Thepotemich [5.8K]

4: Form An Aqueous Solution

This is the only answer that can be observed without testing gear and with the naked eye.... Hope I helped ^-^

5 0

3 years ago

Read 2 more answers

Select the correct answer. Two charged objects, A and B, exert an electric force on each other. What happens if the distance bet

VikaD [51]

Answer:

The electric force between them decreases

Explanation:

The force between two charged particle is given by :

$F=\dfrac{kq_1q_2}{r^2}$

Where

r is the distance between charges

If the distance between the charges is increased, the electric force gets decreased as there is an inverse relation between force and distance.

Hence, the correct option is (c) "The electric force between them decreases"

7 0

2 years ago