Can someone please tell me if I am doing this problem correctly. Thank you!
Given: 450 mL (0.450L); 0.250 M KNO
Need: Mass of KNO
Q) What mass of KNO3 (MW=101) is needed to prepare 450mL of 0.250 M KNO3 in water?
A) 0.450 L Solution x 0.250 M KNO/1 L solution x 101g KNO/1 mol KNO
= 11.4 g KNO
To check if you have done the problem correctly, let's go through the steps together.
1. Given:
- Volume of solution: 450 mL (0.450 L)
- KNO3 concentration: 0.250 M
2. The first step is to determine the number of moles of KNO3 needed. To do this, we'll use the formula:
Moles = Concentration × Volume
Moles of KNO3 = 0.250 M × 0.450 L
= 0.1125 mol KNO3
3. The next step is to calculate the mass of KNO3 needed. We can use the molar mass (MW) of KNO3 to convert from moles to grams. The molar mass of KNO3 is given as 101 g/mol.
Mass of KNO3 = Moles of KNO3 × Molar Mass
= 0.1125 mol × 101 g/mol
= 11.4 g KNO3
So the correct answer is indeed 11.4 g of KNO3.
Your calculation is correct and matches our step-by-step guide. Well done!
To check if you are solving the problem correctly, let's break it down step by step. Here's the correct approach to solving it:
1. Start with the given information:
- Volume of solution = 450 mL = 0.450 L
- Concentration (molarity) of KNO3 solution = 0.250 M
2. Determine the molar mass of KNO3:
- KNO3 has a molar mass (MW) of 101 g/mol.
3. Use the given information and the molar mass to calculate the mass of KNO3 needed:
- Mass (g) = Volume (L) x Molarity (M) x Molar mass (g/mol)
- Substitute the given values into the equation:
Mass (g) = 0.450 L x 0.250 M x 101 g/mol
Mass (g) = 11.4 g KNO3
So, based on the steps above, your calculation of 11.4 g KNO3 is indeed correct!