Question

Calculate the percentage of water in the hydrate manganese (ii) nitrate tetrahydrate

Answer 1

Answer:

Divide the mass of the water lost by the mass of hydrate and multiply by 100.

Explanation:

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Answer 2

Answer:

28.7%

Explanation:

First let us write the formula of manganese (ii) nitrate tetrahydrate. This is shown below:

Mn(NO3)2.4H2O

The molar mass of Mn(NO3)2.4H2O = 55 + 2[14 + (3x16)] + 4[(2x1) + 16]

= 55 + 2[14 + 48] + 4[2 + 16]

= 55 + 2[62] + 4[18]

= 55 + 124 + 72

= 251g/mol

Mass of water of crystallization in Mn(NO3)2.4H2O = 4H2O

= 4[(2x1) + 16]

= 4[2 + 16]

= 4[18]

= 72g

The percentage by mass of water of crystallization in manganese (ii) nitrate tetrahydrate Mn(NO3)2.4H2O, is given by:

Percentage of water of crystallization = Mass of water of crystallization / Molar Mass of Mn(NO3)2.4H2O x 100

= 72/251 x 100

= 28.7%

Therefore the percentage of water of crystallization in manganese (ii) nitrate tetrahydrate is 28.7%