ΔH negative shows that the reaction is spontaneous. Higher value for Zn shows that the reaction is more feasible.
For the reactions, C+O2⟶CO2;ΔH=−393 J 2Zn+O2⟶2ZnO;ΔH=−412 J
Held on 30 Apr 2002 · Verified 6 Jul 2026.
carbon can oxidise Zn
oxidation of carbon is not feasible
oxidation of Zn is not feasible
Zn can oxidise carbon
Sign in to track your attempts and accuracy.
Sign in to keep a private note on this question. Nothing you write is ever public.
The ratio of mass percentage (w/w) of C : H in a hydrocarbon is $12 : 1$. It has two carbon atoms. The weight (in g) of $CO_2(g)$ formed when $3.38$ g of this hydrocarbon is completely burnt in oxygen is : (Given : Molar mass in g mol$^{-1}$ C : 12, H : 1, O : 16)
The correct order of total number of atoms present in<br>(A) $2$ moles of cyclohexane<br>(B) $684$ g of sucrose<br>(C) $90.8$ L of dihydrogen at STP<br>is:
An oxide of iron contains $69.9\%$ iron, its empirical formula, is: (Given: Molar mass of Fe and O are $56$ and $16$ g mol$^{-1}$ respectively.)
What volume of hydrogen gas at STP would be liberated by action of $50\text{ mL}$ of $H_2SO_4$ of $50\%$ purity (density $= 1.3\text{ g mL}^{-1}$) on $20\text{ g}$ of zinc ?<br>Given : Molar mass of H, O, S, Zn are $1, 16, 32, 65\text{ g mol}^{-1}$ respectively.
For the given reaction:<br>$\mathrm{CaCO}_{3}+2 \mathrm{HCl} \longrightarrow \mathrm{CaCl}_{2}+\mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2}$<br>If $90 \mathrm{~g} \mathrm{CaCO}_{3}$ is added to 300 mL of HCl which contains $38.55 \% \mathrm{HCl}$ by mass and has density $1.13 \mathrm{~g} \mathrm{~mL}^{-1}$, then which of the following option is correct ?<br>Given molar mass of $\mathrm{H}, \mathrm{Cl}, \mathrm{Ca}$ and O are 1, 35.5, 40 and $16 \mathrm{~g} \mathrm{~mol}^{-1}$ respectively.
Work through every JEE Main Physical Chemistry PYQ, year by year.