What are two things that characterize the practice of science

What volume of a 5.00M solution of hydrochloric acid contains 8.00mol of HCl?

rjkz [21]

Answer:

520ML and apparently I need to put more in this answer

Explanation:

brainly.com

7 0

3 years ago

"Thermite" reactions have been used for welding metal parts such as railway rails and in metal refining. One such thermite react

frosja888 [35]

<u>Answer:</u> The given reaction is non-spontaneous in nature.

<u>Explanation:</u>

Entropy change is defined as the difference in entropy of all the product and the reactants each multiplied with their respective number of moles.

The equation used to calculate entropy change is of a reaction is:

$\Delta S^o_{rxn}=\sum [n\times \Delta S^o_{(product)}]-\sum [n\times \Delta S^o_{(reactant)}]$

For the given chemical reaction:

$3Mg(s)+Cr_2O_3(s)\rightarrow 3MgO(s)+2Cr(s)$

The equation for the entropy change of the above reaction is:

$\Delta S^o_{rxn}=[(3\times \Delta S^o_{(MgO(s))})+(2\times \Delta S^o_{(Cr(s))})]-[(3\times \Delta S^o_{(Mg(s))})+(1\times \Delta S^o_{(Cr_2O_3(s))})]$

We are given:

$\Delta S^o_{(Mg(s))}=32.68J/K.mol\\\Delta S^o_{(Cr_2O_3(s))}=81.2J/K.mol\\\Delta S^o_{(MgO(s))}=26.94J/K.mol\\\Delta S^o_{(Cr(s))}=23.77J/K.mol$

Putting values in above equation, we get:

$\Delta S^o_{rxn}=[(3\times (26.94))+(2\times (23.77))]-[(3\times (32.68))+(1\times (81.2))]\\\\\Delta S^o_{rxn}=-50.88J/K=-0.0509kJ/K.mol$

For the reaction to be spontaneous, the Gibbs free energy of the reaction must come out to be negative.

To calculate the standard Gibbs free energy of the reaction, we use the equation:

$\Delta G^o=\Delta H^o-T\Delta S^o$

where,

$\Delta G^o$ = standard Gibbs free energy = ?

$\Delta H^o$ = standard enthalpy change of the reaction = 665.1 kJ/mol

T = Temperature = 298.15 K

$\Delta S^o$ = standard entropy change of the reaction = -0.0509 kJ/K.mol

Putting values in above equation, we get:

$\Delta G^o=(665.1kJ/mol)-(298.15K\times (-0.0509kJ/K.mol))=680.27kJ/mol$

As, the Gibbs free energy of the reaction is coming out to be positive, the reaction is non-spontaneous in nature.

Hence, the given reaction is non-spontaneous in nature.

4 0

4 years ago

How much heat is required to melt 15.0 grams of ice at 0.0º C?

uysha [10]

The amount of heat required to melt 15.0 grams of ice at 0.0º C is<u> 4950 J.</u>

<h3>What is the amount of heat required to melt 15.0 grams of ice at 0.0º C?</h3>

The amount of heat required to melt 15.0 grams of ice at 0.0º C is calculated from the formula given below:

Amount of heat = mass * latent heat of fusion of ice

The latent heat of fusion is the amount of heat required to convert a unit mass of ice at 0.0º C to water at 0.0º C

The latent heat of fusion of ice is 330J/g

mass of ice = 15.0 g

Amount of heat required = 15.0 g * 330 J/g

Amount of heat required = 4950 J

Learn more about latent heat of fusion at: brainly.com/question/87248

#SPJ1

4 0

1 year ago

Help me with this answer I really need it

yulyashka [42]

Answer:

THe answer I belive is B

Explanation:

6 0

3 years ago

If I fill a tall glass with water and then transfer the water to a shorter glass, it appears there is more water. Is there more

jasenka [17]

No, there is not more water. It just appears this way because the new glass is smaller and the water takes up more room in it than it did in the larger glass.

3 0

3 years ago