Zapisujemy na Twoim urządzeniu to, bez czego serwis nie działa, np. zalogowanie. Plików analitycznych użyjemy tylko za Twoją zgodą. Szczegóły w polityce prywatności.
Wybierz umiejętność, rok lub poziom trudności.
Pokazujemy tylko poziomy, dla których mamy zadania.
Znaleziono 1476 zadań
In a precipitation reaction, further portions of the excess reactant are added after the limiting reactant has been completely consumed. Which graph shows how the amount of precipitate formed depends on the amount of excess reactant added? A. Graph A B. Graph…
Separate pure samples of the two enantiomers of 2-chlorobutane are available. Which measurement can be used to distinguish between them? A. Boiling point B. Direction in which each rotates plane-polarized light C. Infrared spectrum D. 1H NMR spectrum in an…
Which observation can be used to distinguish between the two enantiomers of a chiral compound in an achiral environment? A. The direction in which plane-polarized light is rotated B. Boiling point C. The mass-to-charge ratio of the molecular ion D. The number…
Which compound produces the high resolution 1H NMR spectrum shown? A. Propanone B. Butanal C. Butanone D. Pentan-3-one
Use section 21 of the data booklet. The high resolution 1H NMR spectrum of an unknown compound is shown. Which compound is it? A. Butane B. Butanone C. Ethoxyethane D. Pentan-3-one
A 2.51 g sample of zinc carbonate is heated until it reaches constant mass. ZnCO3(s) → ZnO(s) + CO2(g) What is the mass of solid remaining? A. 0.88 g B. 1.63 g C. 2.51 g D. 3.39 g
(i) Write a balanced equation for the reaction of calcium with oxygen to form calcium oxide. (ii) Calcium oxide is a basic oxide. Identify an element in period 3 that forms an amphoteric oxide.
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) →…