Question 28 from [1, p. 4.4]: An ideal gas is expanded irreversibly from $\pu{5 L}$ to $\pu{10 L}$ against a constant external pressure of $\pu{1 bar}.$ The value of heat involved $(q)$ in this isenthalpic process is (a) $0$ (b) $\pu{+500 J}$ (c) $\pu{+5 J}$ (d) $\pu{-500 J}$ It ...

Someone asked the question "What is the mass of ozone present in 10.6 g of Na2CO3?". On the user page of the OP, it says "a typical ninth grader". Shouldn't a ninth grader by able to ask a question like that? It is a naive question, and it shows that the English language does not distinguish betw...