Lava is hot liquid rock. When lava flows over solid ground, the solid ground beneath it increases in temperature. What happens to the molecules in the solid ground when the temperature is increasing? The energy of the molecules in the ground decreases.

7 0

3 years ago

A sample of 9.00 grams of aluminum metal is added to an excess of hydrochloric acid. The volume of hydrogen gas produced at stan

marysya [2.9K]

Answer:

The volumen of hydrogen (H) is 11.22 L

Explanation:

The balanced reaction between the aluminum (Al) and the hydrochloric acid (HCl) is:

2Al(s) + 6HCl(l) --> 2AlCl3(ac) + 3H2(g)

It is a reduction-oxidation reaction.

At the beginning we have 9.00 grams of Al what represents an certain amount of moles. Then, we know the molar mass of Al is 26.9815 g/mol, so the moles content in 9.00 g of Al are :

9.00 g Al * (1 mol Al / 26.9815 g Al)= 0.33356 mol Al

Now, we have to conisdered the molar relation between the Al and H2, according to the balanced reaction performed above. That is 2:3 (Al:H2)

Then,

0.33356 mol Al * (3 mol H2/ 2mol Al) = 0.50034 mol H2

In this point, we can considered the H2 like a noble gas, because the question ask for standard temperature and pressure (0° C= 273.15K and 1 atm).

Let us remember the noble gases equation

PV=nRT

P: pressure

V: Volumen

n: number of moles

R: gases constant

T: temperature

For the volumen, the equation is:

V= (nRT/P)

Now: V= (0.50034 mol * 0.0821 (L*atm/K*mol) * 273.15 K)/ (1 atm)

V= 11.22 L

3 0

3 years ago