Zadania z chemii IB HL

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Filtry i umiejętności

A solution has a pH of 4.0 at 298 K. What is the hydroxide ion concentration, [ $\ce{OH-}$ ], in $\mathrm{mol\,dm^{-3}}$

? A. 10 B.

10^{-4}

C.

10^{-10}

D.

10^{-18}

What is the main reason why nitric acid has a lower pH than ethanoic acid of the same concentration? A. Nitric acid is an oxidizing agent. B. Nitric acid ionizes to a greater extent in water. C. The conjugate base of nitric acid is stronger than that of…

Which equation correctly represents a reaction of dilute sulfuric acid? A. $\ce{H2SO4 + MgCO3 -> MgSO4 + CO2 + H2O}$ B. $\ce{H2SO4 + 2Ag -> Ag2SO4 + H2}$ C. $\ce{H2SO4 + 2KOH -> K2SO4 + H2}$ D. $\ce{H2SO4 + 2NaHCO3 -> Na2SO4 + 2H2O}$

Sulfur has different oxidation states in hydrogen sulfide, $\ce{H2S}$ , and in sulfurous acid, $\ce{H2SO3}$ . Which pair of values is correct? A. $\ce{H2S}$ : +2; $\ce{H2SO3}$ : +4 B. $\ce{H2S}$ : −2; $\ce{H2SO3}$ : +6 C. $\ce{H2S}$ : −2; $\ce{H2SO3}$ : +4 D.…

Which salt forms a basic solution when dissolved in water? A. $\ce{KNO3}$ B. $\ce{NH4Br}$ C. $\ce{CH3COOK}$ D. $\ce{NaHSO4}$

The table gives data for four bases at 298 K. Base $K_\mathrm{b}$ p $K_\mathrm{b}$ $\ce{N2H4}$ 5.90 $\ce{C2H5NH2}$ $5.6 \times 10^{-4}$ $\ce{C6H5NH2}$ 9.37 $\ce{C5H5N}$ $1.7 \times 10^{-9}$ Which base has the weakest conjugate acid? A. $\ce{N2H4}$ B.…

Part of the reactivity series of metals is shown, from the most reactive to the least reactive. Mg, Al, Mn, Zn, Fe, Ni, Sn, Pb, Cu, Ag Which reaction is spontaneous? A. $\ce{Fe^{2+}(aq) + Ni(s) -> Ni^{2+}(aq) + Fe(s)}$ B.…

What is the best indicator to use in the titration of propanoic acid with potassium hydroxide? A. Methyl orange, $\mathrm{p}K_\mathrm{a} = 3.7$ B. Bromocresol green, $\mathrm{p}K_\mathrm{a} = 4.7$ C. Bromothymol blue, $\mathrm{p}K_\mathrm{a} = 7.0$ D.…

A buffer solution contains propanoic acid at 0.300 $\mathrm{mol\,dm^{-3}}$ and sodium propanoate at 0.600 $\mathrm{mol\,dm^{-3}}$ . What is its pH? p $K_\mathrm{a}$ (propanoic acid) = 4.87 A. 4.57 B. 4.87 C. 5.17 D. 5.47

Which alcohol and which conditions would give the highest yield of 3-methylbutanoic acid on oxidation with acidified potassium dichromate(VI)? A. 3-methylbutan-2-ol, reflux B. 3-methylbutan-1-ol, distillation C. 3-methylbutan-1-ol, reflux D.…