Zadania z chemii IB HL

Raising the temperature of a reaction mixture by 10 °C can double the rate of reaction, even though the collision frequency increases by only a few per cent. What is the main reason for the large increase in rate? A. The activation energy of the reaction is…

Which expression correctly gives the equilibrium constant for the following reaction? $\ce{2NO(g) + Cl2(g) <=> 2NOCl(g)}$ A. $K_c = \dfrac{[\ce{NOCl}]^2}{[\ce{NO}]^2[\ce{Cl2}]}$ B. $K_c = \dfrac{[\ce{NO}]^2[\ce{Cl2}]}{[\ce{NOCl}]^2}$ C.…

The energy profile of a reaction that occurs in two steps is shown. Which statement is correct? A. Q is a transition state, and the first step is rate-determining. B. Q is an intermediate, and the first step is rate-determining. C. Q is an intermediate, and…

The equation for a reaction between gases X and Y is: $\ce{2X(g) + Y(g) <=> 2Z(g)}$ At equilibrium at 700 K the concentrations of X, Y and Z are $0.50\ \mathrm{mol\,dm^{-3}}$, $0.40\ \mathrm{mol\,dm^{-3}}$ and $1.0\ \mathrm{mol\,dm^{-3}}$ respectively.…

Which reaction is expected to have the largest Arrhenius factor, $A$, at a given temperature? A. $\ce{Cl2(g) + Br2(g) -> 2BrCl(g)}$ B. $\ce{Cl(g) + CH4(g) -> HCl(g) + CH3(g)}$ C. $\ce{C2H4(g) + HBr(g) -> C2H5Br(g)}$ D. $\ce{Cl(g) + Br(g) -> BrCl(g)}$

Which reactions involve the transfer of a proton? I. $\ce{CH3COOH(aq) + NH3(aq) -> CH3COONH4(aq)}$ II. $\ce{2CH3COOH(aq) + Mg(s) -> (CH3COO)2Mg(aq) + H2(g)}$ III. $\ce{CH3COOH(aq) + NaHCO3(s) -> CH3COONa(aq) + H2O(l) + CO2(g)}$ A. I and II only B. I and III…

An indicator, HIn, is a weak acid with $\mathrm{p}K_a = 5.0$. HIn is yellow and its conjugate base, $\ce{In-}$, is blue. $\ce{HIn(aq) <=> H+(aq) + In^-(aq)}$ Which statements are correct? I. At pH 2.0 the indicator appears yellow. II. At pH 5.0 the…

The overall reaction during the discharge of a lead–acid battery is: $\ce{Pb(s) + PbO2(s) + 2H2SO4(aq) -> 2PbSO4(s) + 2H2O(l)}$ Which statement is correct? A. The oxidation state of lead in $\ce{Pb(s)}$ changes from +2 to 0. B. The oxidation state of sulfur…

In a redox titration, dichromate(VI) ions are reduced to chromium(III) ions and iron(II) ions are oxidized to iron(III) ions. $\ce{Cr2O7^2-(aq)}$ reduced to $\ce{Cr^3+(aq)}$ $\ce{Fe^2+(aq)}$ oxidized to $\ce{Fe^3+(aq)}$ What volume of…