Question

(i) what is the mass of 0.5 mole of nh 3 ? Given atomic mass of n = 14 u, atomic mass of (h) = 1 u. (iii) calculate the number of particles in 31g of p4 molecules. Atomic mass of p = 31 u. (iv) find the number of ,ones in 87 g of k2so4. Atomic masses of k = 39 u, s= 32 u, o = 16u.

Answer 1

1- mass of one mol of NH3= 17g

So the mass of 0.5 mole = 8.5 gm

2-No.of moles equals sample mass ÷ molar mass

So no.of moles of P4 = 31÷ (31×4=124)

= 4 moles

No of particles = no.of moles × avogadros no

So no of p atoms = 4×6.02×10^23

Answer 2

Answer:

4*5.02*10^23

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