First of you must know the number of moles to know the molecules of any substance. Here moles of (NH4)2SO4 = weight of (NH4)2SO4/molar mass of (NH4)2SO4 = 3/132 = 0.022 moles. Now multiply number of moles with Avogadro's number to get number of molecules or atoms. Therefore, number of molecules in (NH4)2SO4 = 0.022 x 6.02 x 10^23 = 1.3244 x 10^22 molecules. Hope this helps!
‘2’AgNO3 + Cu -> Cu(NO3)2 + ‘2’Ag
Answer:
6782 has 4, 26.2 has 3, 0.3491 has 4 and 55 has 2 significant figures .
Answer:
Electron geometry- Tetrahedral
Molecular geometry- Bent
Bond angle- <<109.5°
Explanation:
According to the Valence Shell Electron Pair Repulsion (VSEPR) Theory, the shape of a molecule depends on the number of electron pairs present bon the central atom of the molecule. The electron pairs orient themselves as far apart in space as possible to minimize repulsion between electron pairs.
However, the repulsion between all electron pairs is not the same. Lone pairs cause more repulsion around the central atom than bond pairs. Hence lone pairs tend to distort the molecular structure away from that predicted on the basis of Valence Shell Electron Pair Repulsion Theory.
Considering XY2Z2, there are four electron domains, two bond pairs with bonding groups at 180° apart and two lone pairs. Based on VSEPR theory, a tetrahedral shape is expected with a bond angle of about 109°.
The presence of two lone pairs distorts the observed molecular geometry to a bent shape with bond angle <<109°, hence the answer above.