1) Calcola la massa in grammi di 2,5 x 1025 molecole di acido solforoso, H2SO3
2) Un cubetto di argento (densità 10,5 g/cm) ha il lato di 5
cm. Calcola la quantità in moli e il numero di atomi di
argento presenti nel cubetto.
3) Sono contenute più moli di ferro (densità 7,87 g/cm°) in
una sfera di raggio 2 cm o in un cubetto con il lato di 3
cm?
4)Calcolare la composizione percentuale del solfato di
magnesio, MgSO4
5) Un composto puro ha la seguente composizione
percentuale:
49% di C
2,74% di H
48,1% di ci
Determina la formula minima del composto.
6) Calcola la massa molecolare di un gas che a 60 °C e​

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

Clyde and marilyn are riding a roller coaster. during which section(s) of the track is their potential energy converted to kinetic energy? a. from point b to point c only b. from point b to point d only c. from point a to point b only d. from point a to point b and from point c to point d

Pegmatites are igneous rocks in which the individual minerals are very large. typically, the minerals are all light-colored quartz, feldspar and muscovite. if you were given a black and white photograph of a pegmatite in a quarry (where the rock has been blasted and broken), what physical properties could you use to identify those three minerals in this hypothetical photo? describe each mineral and the specific diagnostic properties. be specific.