During which time interval does the substance exist as both a liquid and a solid

Answer:

Endothermic: water formation from ice and a cold instant ice pack  Explanation:

Answer:6.94

Explanation:Atomic mass of Li = 6.94

To find the number of atoms: 12.6 g Li x 1 mole/6.94 g x 6.02x10^23 atom/mole = 1.09x10^24 atoms

Response:

ΔH = -793.6 kJ

Reasoning:

The ΔH for this particular reaction can be calculated through Hess's law, which allows one to combine the ΔH values of the half-reactions to find the overall ΔH:

The half-reactions are as follows:

1) H₂(g) + ¹/₂O₂(g) ⟶ H₂O(g) ΔH₁ = −241.8 kJ

2) X(s) + 2Cl₂(g) ⟶ XCl₄(s) ΔH₂ = +356.9 kJ

3) ¹/₂H₂(g) + ¹/₂Cl₂(g) ⟶ HCl(g) ΔH₃ = −92.3 kJ

4) X(s) + O₂(g) ⟶ XO₂(s) ΔH₄ = −639.1 kJ

5) H₂O(g) ⟶ H₂O(l) ΔH₅ = −44.0 kJ

The calculation involves summing (4) + 4×(3) - (2) - 2×(1) - 2×(5):

(4) X(s) + O₂(g) ⟶ XO₂(s) ΔH = −639.1 kJ

+4×(3) 2H₂(g) + 2Cl₂(g) ⟶ 4HCl(g) ΔH = −369.2 kJ

-(2) XCl₄(s) ⟶ X(s) + 2Cl₂(g) ΔH = -356.9 kJ

-2×(1) 2H₂O(g) ⟶ 2H₂(g) + O₂(g) ΔH = +483.6 kJ

-2×(5) 2H₂O(l) ⟶ 2H₂O(g) ΔH = +88.0 kJ

= XCl₄(s) + 2H₂O(l) ⟶ XO₂(s) + 4HCl(g)

<pThus, ΔH is:

ΔH = -639.1 kJ -369.2 kJ -356.9 kJ +483.6 kJ +88.0 kJ

ΔH = -793.6 kJ

I trust this clarifies things!

To light a Bunsen burner, you should follow these essential steps: First, tidy up the surrounding area and remove any combustible items. Second, shut off the air supply. Third, activate the gas flow to the burner. Fourth, ignite the flame using a lighter. Finally, modify the air intake to regulate the size of the flame.

Density is calculated as Mass divided by Volume.

Volume can also be expressed as Mass divided by Density.

Volume becomes 2 divided by 128.

This results in Volume equal to 1/64.

Therefore, each side measures 4 cm.