Molar mass P2O5 = 31 x 2 + 16 x 5 => 142 g/mol
142 g ---------------- 6.02 x 10²³ molecules
0.920g g ------------ ( molecules )
molecules = 0.920 x ( 6.02 x 10²³ ) / 142
molecules = 5.53 x 10²³ / 142
= 3.89 x 10²¹ molecules
1 molecule P2O5 -------------------------- 7 atoms
3.89 x 10²¹ molecules -------------------- ( atoms )
atoms = ( 3.89 x 10²¹) x 7 / 1
atoms = 2.72 x 10²² atoms of P2O5
hope this helps!
We need a image to answer this sorry
Answer:
The are 10 electrons in nitride
First, we need to determine the half reaction of magnesium. It would be expressed as:
Mg2+ + 2e- = Mg
Given the mass of magnesium metal that is produced, we calculate the total charge of the electrolysis by the relations we can get from the half reaction. We do as follows:
4.50 kg Mg ( 1000 g / 1 kg ) ( 1 mol / 24.305 g ) ( 2 mol e- / 1 mol Mg ) ( 96500 C / 1 mol e- ) = 35733388.2 C
We are given the applied EMF in units of V. This value is equal to J/C. So, 5 V is equal to 5 J/C.
35733388.2 C (5 J/C) = 178666941 J
178666941 J ( 1 kW-h / 3.6x10^6 J ) = 49.63 kW-h
For a candle to burn, it requires a spark, which provides the activation energy for the oxidation reaction of the hydrocarbon making the candle.
It also requires oxygen to facilitate the oxidation of the hydrocarbon.
Therefore the two main requirements of combustion of a candle are oxygen and a spark (or an initial flame)
