HELP!!

I'm doing an experiment to do with phosphorus and plant food and MgNH4P04 6H20
my air dry weight of MgNH4P04 6H20 was 1.31 g
grams of P in plant food was .165 g
% P in plant food is 13.87%
% P205 equivalent to % P above is 63.02%
% P 205 in 10-52-10 is 52%
i then get asked what the theoretical weight of MgNH4P04 6H20 is ???? i have no clue how to find this
thank you

I don't know the question. Could this be the molar mass they want? Molar mass MgNH4PO4.6H2O is 245.4.

To find the theoretical weight of MgNH4P04 6H20, you can use the provided information about the percentage of P in the plant food and the percentage of P205 in the 10-52-10 fertilizer.

Step 1: Calculate the weight of P in the plant food:
Given that the weight of P in the plant food is 0.165 g and the percentage of P in the plant food is 13.87%, you can use the formula:
Weight of P = (Percentage of P / 100) * Weight of plant food
Weight of P = (13.87 / 100) * 0.165 g
Weight of P = 0.0228685 g

Step 2: Calculate the weight of P205 in the plant food:
Given that the percentage of P205 equivalent to the percentage of P above is 63.02%, you can use the formula:
Weight of P205 = (Percentage of P205 / 100) * Weight of P
Weight of P205 = (63.02 / 100) * 0.0228685 g
Weight of P205 = 0.0144197 g

Step 3: Calculate the weight of P205 in MgNH4P04 6H20:
Given that the percentage of P205 in 10-52-10 fertilizer is 52%, you can use the formula:
Weight of P205 in MgNH4P04 6H20 = (Weight of P205 / Percentage of P205 in 10-52-10) * 100
Weight of P205 in MgNH4P04 6H20 = (0.0144197 g / 52%) * 100
Weight of P205 in MgNH4P04 6H20 = (0.0144197 g / 0.52) * 100
Weight of P205 in MgNH4P04 6H20 = 2.77825 g

Step 4: Calculate the theoretical weight of MgNH4P04 6H20:
Given that the weight of P205 in MgNH4P04 6H20 is 2.77825 g, you need to convert it to the weight of MgNH4P04 6H20. The molar mass of P205 is 283.89 g/mol. The molar mass of MgNH4P04 6H20 can be calculated as follows:
Molar mass of MgNH4P04 6H20 = (molar mass of Mg) + (4 * molar mass of H) + molar mass of N + (molar mass of P) + (6 * molar mass of O)
Molar mass of MgNH4P04 6H20 = (24.31 g/mol) + (4 * 1.01 g/mol) + (14.01 g/mol) + (16.00 g/mol) + (6 * 16.00 g/mol)
Molar mass of MgNH4P04 6H20 = 246.19 g/mol

Finally, calculate the theoretical weight of MgNH4P04 6H20:
Theoretical weight of MgNH4P04 6H20 = (Weight of P205 in MgNH4P04 6H20 / Molar mass of P205) * Molar mass of MgNH4P04 6H20
Theoretical weight of MgNH4P04 6H20 = (2.77825 g / 283.89 g/mol) * 246.19 g/mol
Theoretical weight of MgNH4P04 6H20 = 2.41109 g

Therefore, the theoretical weight of MgNH4P04 6H20 is approximately 2.41109 grams.