A box of washing soda leaves the factory containing 1.50 kg of Na2CO3.10H2O (Mr= 286.1). However, a customer complains because he finds that the box appears partly empty and weighs only 1.34 kg. An independent analyst says that the box contains the correct mass of sodium carbonate, but that it has lost water of crystallization. What is the composition of the customer's soda?

i. Na2CO3*1.7 H2O
ii. Na2CO3*5.2 H2O
iii. Na2CO3*8.3 H2O
iv. Na2CO3*8.9 H2O