Explain whether this is a chemical or physical change, and why. does it involve elements, compounds, mixtures, or pure substances?
If the process involves a chemical reaction then surely it is a chemical change where new bonds are being formed from the collision of the reactants.
Describe how many atoms are involved before and after. what do you notice about the number of atoms?
From the balanced chemical reaction, we see that we need 1 mol of N2 gas and 3 mol of H2 in order to form 2 mol of NH3.
Answer: 116g/mole
Explanation:
She didn't get the answer because she didn't add the them well , due to the bracket present.
This problem is describing the state two gases have when separated and together as shown on the attached picture. First of all, diagram 1 shows how they are separated in two containers with apparently equal volumes, whereas diagram 2 shows the removal of the barrier so that they get mixed together.
In this case, we can analyze that each gas has its own pressure and due to the removal of the barrier, both pressure and volume undergo a change. Thus, we can infer that the final volume is doubled with respected to the initial one for each gas, causing the pressure of each gas to be halved and the total pressure the half of the added ones, in agreement to the Boyle's law (inversely proportional relationship between pressure and temperature).
Therefore, the correct choice is:
C. The partial pressure of each gas in the mixture is half its initial pressure; the final total pressure is half the sum of the initial pressures of the two gases.
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Answer:
∆H > 0
∆Srxn <0
∆G >0
∆Suniverse <0
Explanation:
We are informed that the reaction is endothermic. An endothermic reaction is one in which energy is absorbed hence ∆H is positive at all temperatures.
Similarly, absorption of energy leads to a decrease in entropy of the reaction system. Hence the change in entropy of the reaction ∆Sreaction is negative at all temperatures.
The change in free energy for the reaction is positive at all temperatures since ∆S reaction is negative then from ∆G= ∆H - T∆S, we see that given the positive value of ∆H, ∆G must always return a positive value at all temperatures.
Since entropy of the surrounding= - ∆H/T, given that ∆H is positive, ∆S surrounding will be negative at all temperatures. This is so because an endothermic reaction causes the surrounding to cool down.
1.Electrons can be transferred from one atom to another.
2.Electrons can be shared between neighbouring atoms.
3.Electrons can be shared with all atoms in a material.