<u>Given:</u>
Calculated density values-
Aluminum = 2.7 g/cm3
Copper = 9.0 g/cm3
Iron = 7.9 g/cm3
Titanium = 4.8 g/cm3
Unknown sample mass = 9.5 g
Sample volume = 2.1 cm3
<u>To determine:</u>
The identity of the unknown sample
<u>Explanation:</u>
'Density' is a physical parameter which can be used to identify the nature of the unknown substance.
Density = Mass/Volume
For the unknown sample
Density = 9.5 g/2.1 cm3 = 4.52 g/cm3
This matches closely with the calculated density of titanium
Ans: The unknown substance is made of titanium
Answer:
We normally separate unreacted hydrogen from ammonia (product) in Haber process. The reaction mixture contains some ammonia, plus a lot of unreacted hydrogen and nitrogen. The mixture is cooled and compressed, causing the ammonia gas to condense into a liquid.
Answer:
Option B. A
Explanation:
From the question given above, the following data were obtained:
C(s) + 2H₂ (g) —> CH₄ (g). ΔH = –74.9 kJ
From the reaction above, we can see that the enthalpy change (ΔH) is negative (i.e –74.9 KJ) which implies that the heat content of the reactants is greater than the heat content of the products. Thus, the reaction is exothermic reaction.
For an exothermic reaction, the energy profile diagram is drawn in such a way that the heat content of reactants is higher than the heat content of products because the enthalpy change
(ΔH) is always negative.
Thus, diagram A (i.e option B) gives the correct answer to the question.
A bimolecular reaction is always a second-order reaction, but a second-order reaction is not always a bimolecular reaction.
The most important thing to take note of is that molecularity of a reaction is a concept applicable to only elementary reactions, meaning non-complex. In a way, elementary reactions are basic and achieved in one step. Complex reactions involve intermediate steps before achieving the desired reaction.
Molecularity is equal to the sum of the coefficients of the reactants, so two reactants give a second-order bimolecular reaction. However, second-order reactions can involve more than two reactants especially in complex reactions.
Answer/Explanation:
Wave W is being diffracted, Wave X is being reflected, and waves Y and Z are being refracted.
