Help please I’m confused

Choose all the answers that apply. Which of the following has kinetic energy? rolling ball, moving car, book on a table, spinnin

Virty [35]

Spinning top, moving car, and rolling ball have kinetic energy I believe

5 0

3 years ago

Chemitey half equations

shepuryov [24]

Isn't it a because in b at the start of the equation the E in Fe just disappeared

8 0

3 years ago

Given the following thermodynamic data, calculate the lattice energy of LiCl:

tiny-mole [99]

Answer:

$\boxed{\text{-862 kJ/mol}}$

Explanation:

One way to calculate the lattice energy is to use Hess's Law.

The lattice energy U is the energy released when the gaseous ions combine to form a solid ionic crystal:

Li⁺(g) + Cl⁻(g) ⟶ LiCl(s); U = ?

We must generate this reaction rom the equations given.

(1) Li(s) + ½Cl₂ (g) ⟶ LiCl(s); ΔHf° = -409 kJ·mol⁻¹

(2) Li(s) ⟶ Li(g); ΔHsub = 161 kJ·mol⁻¹

(3) Cl₂(g) ⟶ 2Cl(g) BE = 243 kJ·mol⁻¹

(4) Li(g) ⟶Li⁺(g) +e⁻ IE₁ = 520 kJ·mol⁻¹

(5) Cl(g) + e⁻ ⟶ Cl⁻(g) EA₁ = -349 kJ·mol⁻¹

Now, we put these equations together to get the lattice energy.

(5) Li⁺(g) +e⁻ ⟶ Li(g) 520

(6) Li(g) ⟶ Li(s) -161

(7) Li(s) + ½Cl₂(g) ⟶ LiCl(s) -409

(8) Cl(g) ⟶ ½Cl₂(g) -121.5

(9) Cl⁻(g) ⟶ Cl(g) + e⁻ <u>+349</u>

Li⁺(g) + Cl⁻(g) ⟶ LiCl(s) -862

The lattice energy of LiCl is $\boxed{\textbf{-862 kJ/mol}}$ .

3 0

3 years ago

How do you convert from grams to moles?

ludmilkaskok [199]

Each element or compound has a molar mass, which is calculated by multiplying the atomic mass of each element by the amount of atoms of that element, and summing the results of each element. The molar mass is measured in g/mol. So you divide the mass in grams by the molar mass to get the amount of moles.

Example:

There are 5g of water.

Calculate the amount of moles.

The water's formula is H2O, so the molar mass of it is

$2 \times 1 + 1 \times 16 = 18$

g/mol.

The amount of moles is:

5g ÷ 18g/mol ~ 0.28mol

5 0

3 years ago

What does 3.5 degree of unsaturation tell you?

Kaylis [27]

Answer:

It means the chemical entity is a radical

Explanation:

When we talk of unsaturation, we are referring to the number of pi-bonds in a chemical entity. The alkane, alkene and alkyne organic family are used to as common examples to explain the term unsaturation.

While alkynes have 3 bonds, it must be understood that they have 2 pi bonds only and as such their degree of saturation is two.

In the case of an alkene, there is only one single pi bond and as such the degree of unsaturation is 1.

Now in this case, we have a fractional 0.5 degree of unsaturation alongside the 3 to make a total of 3.5. So what’s the issue here?

The fractional part shows that the chemical entity we are dealing with here is a radical. While the integer 3 shows that there are 3 pi-bonds, the half pi bond remaining tells us that there is a missing electron on one of the atoms involved in the chemical bonding and as such, the 1/2 extra degree of unsaturation tends to tell us this.

Kindly recall that a radical is a chemical entity within which we have at the least an unpaired electron.

5 0

3 years ago