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2 years ago

Would you expect O₂(g) → 2O(g) to have a positive or a negative ΔH? Explain.

1 answer:

3 0

∆H (enthalpy change) should be positive because you would need energy to break the oxygen- oxygen bond to generate 2 molecules of Oxygen .

<h3>What is enthalpy change ?</h3>

It is type of energy or the measurement of energy . The quantity of enthalpy equals to the total content of heat of a system .

It can be defined as the sum of total internal energy and the product of volume and pressure .

It describes the system is endothermic or exothermic .

<h3>What is exothermic reaction? </h3>

It is a reaction in which energy is released from the system in the form of heat and light.

in this loss of energy occurs. energy liberated from system to surrounding. the enthalpy change i.e. ∆H<0.

<h3>What is endothermic reaction? </h3>

It is a reaction in which energy is absorbed from the surrounding to the system. in this gain of energy occurs. the enthalpy change i.e ∆H>0.

Learn more about enthalpy change here:

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You might be interested in

The ability of a substance to be hammered or rolled into thin sheets is called ________

zaharov [31]

Answer: Malleability

Explanation: is a physical property of metals that defines their ability to be hammered, pressed, or rolled into thin sheets without breaking. In other words, it is the property of a metal to deform under compression and take on a new shape.

3 0

3 years ago

How do you do these?

Agata [3.3K]

Solve these problems like weighted averages:

The first one:

Multiply the masses (isotope numbers) by the decimal form of the percentage. Add them

0.076 (6) + 0.924 (7) = 6.924

The second one:

0.2 (10) + 0.8 (11) = 10.8

If you think about it, these answers make sense. 6.924 is much closer to 7 than to 6 (since there's a lot more lithium-7 than there is lithium-6). 10.8 is closer to 11 than to 10.

6 0

3 years ago

From the value Kf=1.2×109 for Ni(NH3)62+, calculate the concentration of NH3 required to just dissolve 0.016 mol of NiC2O4 (Ksp

Nina [5.8K]

<u>Answer:</u> The concentration of $NH_3$ required will be 0.285 M.

<u>Explanation:</u>

To calculate the molarity of $NiC_2O_4$ , we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles of $NiC_2O_4$ = 0.016 moles

Volume of solution = 1 L

Putting values in above equation, we get:

$\text{Molarity of }NiC_2O_4=\frac{0.016mol}{1L}=0.016M$

For the given chemical equations:

$NiC_2O_4(s)\rightleftharpoons Ni^{2+}(aq.)+C_2O_4^{2-}(aq.);K_{sp}=4.0\times 10^{-10}$

$Ni^{2+}(aq.)+6NH_3(aq.)\rightleftharpoons [Ni(NH_3)_6]^{2+}+C_2O_4^{2-}(aq.);K_f=1.2\times 10^9$

Net equation: $NiC_2O_4(s)+6NH_3(aq.)\rightleftharpoons [Ni(NH_3)_6]^{2+}+C_2O_4^{2-}(aq.);K=?$

To calculate the equilibrium constant, K for above equation, we get:

$K=K_{sp}\times K_f\\K=(4.0\times 10^{-10})\times (1.2\times 10^9)=0.48$

The expression for equilibrium constant of above equation is:

$K=\frac{[C_2O_4^{2-}][[Ni(NH_3)_6]^{2+}]}{[NiC_2O_4][NH_3]^6}$

As, $NiC_2O_4$ is a solid, so its activity is taken as 1 and so for $C_2O_4^{2-}$

We are given:

$[[Ni(NH_3)_6]^{2+}]=0.016M$

Putting values in above equations, we get:

$0.48=\frac{0.016}{[NH_3]^6}}$

$[NH_3]=0.285M$

Hence, the concentration of $NH_3$ required will be 0.285 M.

7 0

3 years ago

Why potasium more reactive than lithium and sodium

frez [133]

So potassium is more reactive than lithium because the outer electron of a potassium atom is further from its nucleus than the outer electron of a lithium atom. Hope this answers the question. Have a nice day. Feel free to ask more questions.

5 0

3 years ago

Which scientist would best describe the motion of the earth?

Burka [1]

I think kepler would be the one to best describe the motion of hte earth because he has a space telescope named after him

5 0

3 years ago