Zadania wzorowane na pytaniach z tego arkusza: te same umiejętności, format i punktacja, inne dane i kontekst. Treści arkusza IB nie publikujemy.
Dodaj cały arkusz do zestawu(i) Write a balanced equation for the reaction of calcium with oxygen to form calcium oxide. (ii) State the block of the periodic table in which calcium is located. (iii) Calcium oxide is a basic oxide. Identify an element in period 3 that forms an amphoteric…
In an experiment, calcium turnings were heated strongly in a crucible with a lid. The following data were recorded: (i) Calculate the amount of calcium, in mol, that was used. (ii) Determine the percentage uncertainty in the final mass of product. (iii) Assume…
A student heated 3.492 g of calcium turnings in a crucible with a lid and obtained 4.490 g of solid product. If the product is assumed to be calcium oxide only, the percentage yield is 92 %. (i) Evaluate whether the formation of calcium nitride, rather than…
The presence of calcium nitride in the product can be demonstrated by adding water. The nitride is hydrolysed to form calcium hydroxide and ammonia. (i) Calculate coefficients that balance the equation for the reaction: __ Ca3N2(s) + __ H2O(l) →…
Most oxide ions are . (i) State the number of protons, neutrons and electrons in this ion. (ii) Some oxide ions are . State the term that describes the relationship between and . (iii) The…
Atoms were once thought to be the smallest particles of matter, impossible to divide. Suggest two pieces of evidence that show an atom has an internal structure.
State the type of bonding in calcium, nitrogen and calcium nitride, and how the valence electrons produce each type of bonding.
Complete the boxes with arrows to show the ground-state electron configuration of an oxygen atom.
Draw the Lewis (electron dot) structure of a molecule of methanol, CH3OH, showing all valence electrons.
Methanol is manufactured from carbon monoxide and hydrogen. The reaction involves the equilibrium: CO(g) + 2 H2(g) ⇌ CH3OH(g) (i) Deduce the expression for the equilibrium constant, Kc, for this equation. (ii) Explain why an increase in pressure…
Whether a higher temperature favours the formation of methanol depends on the enthalpy change of the reaction CO(g) + 2 H2(g) → CH3OH(g) (i) Determine the enthalpy change, ΔH, for the production of methanol, in kJ, using bond enthalpies. Use…
Methylamine is a gas that dissolves in water to form an alkaline solution: CH3NH2(aq) + H2O(l) ⇌ CH3NH3+(aq) + OH−(aq) (i) State the relationship between CH3NH3+ and CH3NH2 in terms of the Brønsted-Lowry theory. (ii) A sample of…
Zinc can be obtained by the electrolysis of molten zinc chloride, ZnCl2. Write the half-equation for the formation of zinc at the negative electrode.
Suggest an experiment that shows that zinc is more reactive than copper, giving the observation that would confirm this.
In one overall reaction, a carbonyl compound, Compound A, reacts with methylmagnesium iodide and the product is then treated with water: Compound A + CH3MgI + H2O → Compound B + Mg(OH)I (i) State the IUPAC name of Compound A. (ii) Identify…
Compound B, shown below, can also be made by the hydration of an alkene. The same reaction also gives a smaller amount of the isomer 3-methylbutan-2-ol, (CH3)2CHCH(OH)CH3. (i) Draw the structural formula of the alkene that is needed. (ii) Deduce the…
Compound B is shown below. Deduce what would be observed when each of Compound B and pentan-2-ol is warmed separately with acidified aqueous potassium dichromate(VI).
Bromoethane can be converted into ethanol: CH3CH2Br + HO− → CH3CH2OH + Br− (i) Identify the type of reaction. (ii) Outline what must be true of a collision between reacting particles for a reaction to occur. (iii) Carbon-halogen bonds are polar, which…