Cl is highly reactive. We know NaCl to

Aluminum chloride can be formed from its elements:

saul85 [17]

Answer: The $\Deltas H^o_{formation}$ for the reaction is -1406.8 kJ.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The chemical reaction for the formation reaction of $AlCl_3$ is:

$2Al(s)+3Cl_2(g)\rightarrow 2AlCl_3 (s)$ $\Delta H^o_{formation}=?$

The intermediate balanced chemical reaction are:

(1) $HCl(g)\rightarrow HCl(aq.)$ $\Delta H_1=-74.8kJ$ ( × 6)

(2) $H_2(g)+Cl_2(g)\rightarrow 2HCl(g)$ $\Delta H_2=-185kJ$ ( × 3)

(3) $AlCl_3(aq.)\rightarrow AlCl_3(s)$ $\Delta H_3=+323kJ$ ( × 2)

(4) $2Al(s)+6HCl(aq.)\rightarrow 2AlCl_3(aq.)+3H_2(g)$ $\Delta H_4=-1049kJ$

The expression for enthalpy of formation of $AlCl_3$ is,

$\Delta H^o_{formation}=[6\times \Delta H_1]+[3\times \Delta H_2]+[2\times \Delta H_3]+[1\times \Delta H_4]$

Putting values in above equation, we get:

$\Delta H^o_{formation}=[(-74.8\times 6)+(-185\times 3)+(323\times 2)+(-1049\times 1)]=-1406.8kJ$

Hence, the $\Deltas H^o_{formation}$ for the reaction is -1406.8 kJ.

6 0

3 years ago

Part A

velikii [3]

Answer: The layers are ordered by density, with the least dense layer on top, and the densest layer on the bottom.

Explanation:

Plato

5 0

3 years ago

How many moles of oxygen are in 52.5 grams of oxygen gas?

adell [148]

An oxygen gas is a diatomic molecule which means that each molecule is composed of 2 atoms. Its symbol is O2.

Each oxygen atom has a molar mass of 16 g/mol. The molar mass of oxygen gas is calculated below,
molar mass = 2 x (16 g/mol) = 32 g/mol

To determine the number of moles in 52.5 grams of oxygen, divide the given mass by the calculated molar mass.

n = 52.5 grams / (32 gram/ mol)
n = 1.64 moles

Thus, there are 1.64 moles of oxygen gas.

3 0

3 years ago

How many particles are in 1 mol of carbon? 1 mol of lithium? 1 mol of eggs? will 1 mol of each of these substances have the same

andrezito [222]

One mole of a substance contains Avogadro's number of atoms/molecules/the like. This would mean that all of the items described would have approximately 6.022 * 10^23 atoms, even though their masses would differ. This would be due to the molar mass of each substance being different because of the constituent elements in the substance.

8 0

3 years ago

Please help

lisabon 2012 [21]

Answer:

There are 2 hydrogen atoms, one magnesium atom, and 5 atoms in total.

Explanation:

We are given a compound in formula form. To make things easier to understand, we can first convert this to the name of the compound.

When a compound contains one or more elements in parentheses, these are usually a polyatomic ion.
Polyatomic ions are ions made up of two or more elements with a positive or negative charge over the entire ion. Commons examples of these NH₄⁺ (ammonia) and HCO₃⁻ (bicarbonate).
You can combine metals with polyatomic ions to create commonly known compounds, such as baking soda. The chemical name for baking soda is sodium bicarbonate, so we can combine Na (sodium) with HCO₃⁻ (bicarbonate) and create sodium bicarbonate: NaHCO₃.

This compound is one magnesium atom bonded to two hydroxide ions.

Hydroxide is the compound between one hydrogen atom and one oxygen atom. The compound overall adopts a negative charge of 1.
If we have one hydrogen atom and one oxygen atom, the most electronegative atom is written first in chemical formulas. Therefore, the symbol for Oxygen (O) goes first.
Then, write in the hydrogen atom directly after the O symbol: OH.
Finally, since we have a negative charge on the ion, we need to play a negative sign as a superscript for the compound. Therefore, this becomes OH⁻.

Now, we need to determine the charge on the Magnesium atom which is determined from the amount of valence electrons the atom has.

On a periodic table, the symbol for Magnesium is Mg and this element has 2 valence electrons.
In order to fulfill the Octet Rule, the It is more likely to give up 2 electrons to a nonmetal than it is to gain 6, so we can safely assume that the charge is ²⁺.
We need to use the criss-cross technique to transfer the charges between the element and the ion, so the negative 1 charge goes to the Mg, which does not appear (negative 1 or positive 1 are implied) and since the magnesium has a charge of positive 2, this is the subscript for the hydroxide ion.
Therefore, our compound becomes Mg(OH)₂, and we have labeled this as magnesium hydroxide.

Now, to the number of atoms:

The new charge on Mg is 1-, so there is only one atom of Mg.
The charge is 2+ on the OH ion, so there are two atoms of H and two atoms of O.
Two atoms of oxygen, two atoms of hydrogen, and one atom of magnesium add up to be five atoms in total.

3 0

3 years ago