Question

1. how many grams of k⁺ are present in 4.73 grams of potassium nitrate? 2. how many grams of potassium nitrate contain 2.13 grams of k⁺? 5 more group attempts remaining. use the references to access important values if needed for this question.

Explanation:

Step1: Determine molar - mass of potassium nitrate (KNO₃)

The molar mass of K (potassium) is approximately 39.1 g/mol, N (nitrogen) is approximately 14.0 g/mol, and O (oxygen) is approximately 16.0 g/mol. The molar mass of KNO₃ is $M = 39.1+14.0 + 3\times16.0=39.1 + 14.0+48.0 = 101.1$ g/mol. The molar mass of K⁺ is 39.1 g/mol.

Step2: Solve for the amount of K⁺ in 4.73 g of KNO₃ (Question 1)

The mass - percentage of K in KNO₃ is $\omega=\frac{39.1}{101.1}$. Let the mass of K⁺ in 4.73 g of KNO₃ be $m_{K^+}$. Then $m_{K^+}=4.73\times\frac{39.1}{101.1}$.
$m_{K^+}=4.73\times\frac{39.1}{101.1}=\frac{4.73\times39.1}{101.1}=\frac{184.943}{101.1}\approx1.83$ g.

Step3: Solve for the mass of KNO₃ containing 2.13 g of K⁺ (Question 2)

Let the mass of KNO₃ be $m$. We know that $\frac{39.1}{101.1}=\frac{2.13}{m}$. Cross - multiply to get $39.1m = 2.13\times101.1$. Then $m=\frac{2.13\times101.1}{39.1}=\frac{215.343}{39.1}\approx5.51$ g.

Answer:

1. 1.83 g
2. 5.51 g