Mole number of 75 g is 0.4 mol. NO2 is 0.8 mol and is 36.8 g.
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.
What do you mean by ‘which of the following’? Without that I am not able to answer the question
Answer:
339.2K
Explanation:
Using Charles law equation;
V1/T1 = V2/T2
Where;
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information provided in this question,
V1 = 2.97 L
V2 = 3.42 L
T1 = 21.6°C = 21.6 + 273 = 294.6K
T2 = ?
Using V1/T1 = V2/T2
2.97/294.6 = 3.42/T2
Cross multiply
2.97 × T2 = 294.6 × 3.42
2.97T2 = 1007.532
T2 = 1007.532 ÷ 2.97
T2 = 339.236
The final temperature is 339.2K
Answer:
Polycyclic aromatic hydrocarbons (from petroleum)
Explanation:
Polycyclic aromatic hydrocarbons (PAH) is a group of compounds which contain more than one aromatic ring. Typically examples include; naphthalene, anthracene, phenanthrene etc.
PAH are present in petroleum products. Almost everyone is regularly exposed to vehicles or other equipments that uses petroleum products as fuel. PAH is usually released from the combustion engine of these equipments and may be inhaled by humans. Thus there is a very high risk of PAH exposure compared to other items listed in the question.
PAHs are known to cause different kinds of cancer and other types of health issues in the body. The most disturbing toxicity of PAH is its carcinogenicity which makes it a very serious potential health risk for humans exposed to it on regular basis.
