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4 years ago

Please select the best answer and click "submit."

1 answer:

vladimir1956 [14]4 years ago

5 0

When it comes to physical changes like phase changes, there are two types of heat energy: sensible heat and latent heat. Sensible heat is the heat absorbed/released when you heat the substance but it doesn't change phase. An example would be heating lukewarm water. The substance is liquid all throughout. Latent heat, on the other hand, is the heat absorbed/released when there is a phase change. An example would be boiling water, because it changes liquid to vapor.

Hence, for freezing liquid, you use the latent heat, specifically the heat of fusion. The answer should be

2.5 g * (1 mol/18.02 g) * 6.03 kJ/mol = 0.84 kJ/mol

The answer is not in the choices. You only use Hvap if you boil water.

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What must the value of a conversion factor always be?

storchak [24]

Answer:

One or unity or 1

Explanation:

For example,

1 min =60 s

If we divide each side of the equation by 1 min, we get

$1 = \dfrac{\text{60 s}}{\text{1 min}}$

If we divide each side of the equation by 60 s, we get

$\dfrac{\text{1 min}}{\text{60 s}} = 1\\\\\text{Thus, both conversion factors, $\dfrac{\text{60 s}}{\text{1 min}}$ and $\dfrac{\text{1 min}}{\text{60 s}}$, equal 1.}$

8 0

3 years ago

BlackZzzverrR [31]

Answer:

here is your answer

enjoy

7 0

3 years ago

If 550 mL of a 3.50 M KCl solution are set aside and alowed to evaporate unti the

andrezito [222]

1) list givens and convert if necessary

C₁ = 3.50 mol/L

V₁ = 0.550 L

C₂ = ?

V₂ = 0.275 L

2) rearrange formula

$C_{1}V_{1}=C_{2}V_{2}\\\\C_{2}=\frac{C_{1}V_{1}}{V_{2}}$

3) solve

$C_{2}=\frac{(3.50\ mol/L)(0.550\ L)}{(0.275\ L)}$

C₂ = 7.00 mol/L

5 0

3 years ago

A chemist must dilute of aqueous potassium dichromate solution until the concentration falls to . He'll do this by adding distil

Phantasy [73]

The question is incomplete; the complete question is;

A chemist must dilute 99.4 mL of 152 mM aqueous potassium dichromate (K_2Cr_2O_7) solution until the concentration falls to 55.0 mM He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits.

Answer:

0.275 L

Explanation:

From C1V1 = C2V2

Where;

C1= initial concentration of the solution 152 × 10^-3 M

V1= initial volume of the solution = 99.4 × 10^-3 L

C2 = concentration after dilution = 55 × 10^-3 M

V2 = volume after dilution = the unknown

V2 = C1 V1/C2

V2 = 152 × 10^-3 × 99.4 × 10^-3 / 55 × 10^-3

V2 = 0.275 L

5 0

3 years ago

water is considered as a compound of hydrogen and oxygen and not a mixture of hydrogen and oxygen and comment on it

HACTEHA [7]

Wat is considered a compound of hydrogen and oxygen and not a mixture because hydrogen and oxygen have gone through a chemical process to form the compound h2O. A mixture can generally be easily separated whereas a compound must undergo another chemical process to separate its elements. Therefore to separate oxygen and hydrogen from water a chemical process is necessary.

4 0

4 years ago