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3 years ago

ΔH is always positive for a ...........

Chemistry

1 answer:

scoray [572]3 years ago

8 0

Answer:

a. endothermic reaction

Explanation:

In an endothermic reaction, heat is absorbed from the environment. This leaves the surrounding at a colder temperature compared to the system.

ΔH, the change in enthalpy is assigned a positive sign because the heat energy level of the final state is higher than that of the initial state.

Some examples are mostly dissolution substances in water.

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What is the resistance of a fluid on an object?

Ainat [17]

Fluid resistance refers to the forces a fluid places on a moving object in the opposite direction to the movement, also known as drag. Drag is the force created by a fluid to resist the motion of an object through it. There are 2 main sources of drag: pressure (form) and friction.

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3 years ago

Carbon disulfide is prepared by heating sulfur and charcoal. The chemical equation is S2(g)+C(s)↽−−⇀CS2(g)????c=9.40 at 900 K Ho

Maru [420]

Answer : The mass of $CS_2$ is, 555.028 grams

Explanation :

First er have to calculate the concentration of $S_2$ .

$\text{Concentration of }S_2=\frac{\text{Moles of }S_2}{\text{Volume of solution}}=\frac{8.08mole}{5.35L}=1.51mole/L$

Now we have to calculate the concentration of $CS_2$ .

The given balanced chemical reaction is,

$S_2(g)+C(s)\rightleftharpoons CS_2(g)$

Initial conc. 1.51 0 0

At eqm. conc. (1.51-x) (x) (x)

The expression for equilibrium constant for this reaction will be,

$K_c=\frac{[CS_2]}{[S_2]}$

Now put all the given values in this expression, we get :

$9.40=\frac{x}{(1.51-x)}$

By solving the term 'x', we get :

x = 1.365 M

Concentration of $CS_2$ = x M = 1.365 M

Now we have to calculate the moles of $CS_2$ .

$\text{Moles of }CS_2=\text{Concentration of }CS_2}\times \text{Volume of solution}=1.365mole/L\times 5.35L=7.303mole$

Now we have to calculate the mass of $CS_2$ .

Molar mass of $CS_2$ = 76 g/mole

$\text{Mass of }CS_2=\text{Moles of }CS_2}\times \text{molar mass of }CS_2}=7.303mole\times 76g/mole=555.028g$

Therefore, the mass of $CS_2$ is, 555.028 grams

3 0

4 years ago

The molecule CH20 contains two single bonds and one double bond.<br> True<br> False

dem82 [27]

Answer:

True

Explanation:

The molecule CH20 contains two single bonds and one double bond.

6 0

3 years ago

If 38 gr of water are produced in reaction, how many mole are CO2 are produced.

Nataly_w [17]

0.86 moles of CO2 - i’m not sure if this is right but it should be something like that

6 0

3 years ago

Which of the following electron configurations of outer sublevels is the most stable?

Natalka [10]

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
4d5 5s1 is where electron configurations of outer sublevels is the most stable. <span>this could be a tricky question because of the fact the respond is going against the final rule that could say that 4d4 5s2 is the main sturdy. the final 2 a merely nonsence there is not any such factor as s3 or s4</span>

4 0

4 years ago