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2 years ago

Need help with these two, solve only the ones you can though :D

Chemistry

1 answer:

ad-work [718]2 years ago

7 0

Answer: 27 is A and 28 is C.

Explanation: I’ll explain 28 but not 27 because that’s just definitions.

In CuSO4 there is a Cu, an S, and 4 O molecules. Add them up you get 6.

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An isomer with a branched structure will require:

Contact [7]

The branched structure isomer will require less energy to melt than the straight chain isomer

explanation
Branched structure isomer has weak intermolecular forces of attraction as compared to straight chain isomers. In addition the branched isomer has a low boiling point as compared to straight chain isomers. Since boiling require the of the intermolecular forces tend to have lower boiling point than straight chain

8 0

3 years ago

Select all that apply. choose the two correct statements below. the elements of the halogen family are very reactive because: th

Harman [31]

Halogens are a group of elements consisting of Fluorine, Chlorine, Bromine, Iodine and Astatine. In their ionic form, they have a superscript of -1, for example, chloride ion is Cl-1. These means that they readily accept one electron in order to achieve the Octet rule. The Octet rule states that each atom must contain 8 electrons in their valence shell for it to be stable. The most stable set of elements are the noble gases. Because they already fulfill the Octet rule, they no longer take part in reactions. Halogens are also very electronegative, meaning, they attract more electrons toward them. This is also a consequence of the Octet rule.

From the choices, the answers would be:
they require only one electron to complete their outer shell
they have a high electronegativity

6 0

3 years ago

Which element is used for the shiny trim on cars

galben [10]

The correct answer is either Chrome (Chromium), or Aluminum. Unlike steel, these two don't rust easily and can be polished to be quite shiny, especially Chromium, which is why you'll always hear people who like cars talking about chrome wheels and chrome spoilers and things like that. They are not that good for bumpy or roads that are full of holes because they can bend much easier than steel so it can be expensive to maintain.

7 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.

E/kJ

(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⁻ +349

Li⁺(g) + Cl⁻(g) ⟶ LiCl(s) -862

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

3 0

2 years ago

A certain ore is 37.3% nickel by mass how many kilograms of this ore would you need to dig up to have 10.0g of nickel

jeka57 [31]

If the grade of the ore is 37.3% nickel, then the unknown quantity to get 10 grams of nickel is 0.373 x = 10 grams or x = 10/0.373=26.8 grams or 0.0268 kg needed to dig up to recover the 10 grams of nickel. At this grade of ore, 1 kilogram would yield 373 grams of nickel.

7 0

3 years ago