<u>Answer:</u> The mass of iron (III) nitrate is 11.16 g/mol
<u>Explanation:</u>
To calculate the mass of solute, we use the equation used to calculate the molarity of solution:

We are given:
Molarity of solution = 0.3556 M
Molar mass of Iron (III) nitrate = 241.86 g/mol
Volume of solution = 129.8 mL
Putting values in above equation, we get:

Hence, the mass of iron (III) nitrate is 11.16 g/mol
321.1 g of strontium phosphite will contain 0.76 moles of strontium phosphite in the beaker.
<u>Explanation:</u>
It is known that 1 mole of any substance is equal to the molar mass of that substance. So for the case of strontium phosphite, the molar mass is found to be 420.8 g/mol.
This means 1 mole of Strontium phosphite will contain 420.8 g of strontium phosphite.
Then 1 g of strontium phosphite will have
moles of strontium phosphite.
So, 321.1 g of strontium phosphite will contain 
Thus, 321.1 g of strontium phosphite will contain 0.76 moles of strontium phosphite in the beaker.
Using accurate measurements, using pure chemicals and performing the reaction under the most ideal conditions is important to get a valuable percent yield.
<h3>How we calculate the percent yield?</h3>
Percent yield of any chemical reaction is define as the ratios of the actual yield to the theoretical yield of the product and multiply by the 100.
To get the high percent yield or actual yield of any reaction, we have to perform the reaction under ideal condition because if we not use the standard condition then we get the low rate of reaction. Reactants should be present in the pure form as impurity make unwanted products and reduce the productivity of main product and accurate amount of reactants also important for the spontaneous reaction.
Hence, options (a), (b) & (c) are correct.
To know more about percent yield, visit the below link:
brainly.com/question/8638404
chemical potential energy, thermal energy, electrical energy, sound energy
Explanation:
the coal is chemical potential energy because it is just sitting there, the coal fueled power plant is thermal energy because it is using the heat from the coal to work the power plant, that is then turned into electrical energy, which then goes to the radio which displays sound energy
<h2>
pls give brainliest</h2>