Answer:
7,38 g of K₃PO₄
Explanation:
Molarity is an unit of chemical concentration. 0,139 M means 0,139 moles of solute per liter of solution.
In this case, the solute is potassium phosphate (K₃PO₄; molar mass: 212,27 g/mol) and the volume of the solution must be 250mL≡0,25L.
Thus, the moles of potassium phosphate you need are:
0,139 mol/L×0,25L = 0,03475 moles of K₃PO₄
In grams:
0,03475 moles of K₃PO₄ ×
= 7,38 g of K₃PO₄
I hope it helps!
<span>To calculate the average mass of the element, we take the summation of the product of the isotope mass and the percent abundance. In this case, it is 0.9963 * 14.003 amu + 0.0037* 15.00 amu. This is equal to an average mass of 14.00668889 amu.</span>
Answer: The empirical formula for the given compound is 
Explanation : Given,
Percentage of H = 18 %
Percentage of N = 82 %
Let the mass of compound be 100 g. So, percentages given are taken as mass.
Mass of H = 18 g
Mass of N = 82 g
To formulate the empirical formula, we need to follow some steps:
Step 1: Converting the given masses into moles.
Moles of Hydrogen = 
Moles of Nitrogen = 
Step 2: Calculating the mole ratio of the given elements.
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 5.8 moles.
For Hydrogen = 
For Nitrogen = 
Step 3: Taking the mole ratio as their subscripts.
The ratio of H : N = 3 : 1
Hence, the empirical formula for the given compound is 