calculate the mass and prepare 200ml 0.1M, 250 ml 0.2 N, 100 ml 3% of NaCl, Na2Co3 solution
You will have to find the molar mass here..
200 ml * 0.1 mol/ L * 1 L/ 1000 mL= 0.02M
250 ml* 0.2M/ L * 1L/ 1000 mL= 0.05M N
I somehow feel this problem is incomplete or either I am unable to understand the chemical compound name. Is there anymore to it?
You have six problems here. Three are for NaCl and three for Na2CO3.
For NaCl:
200 mL of 0.1M:
How many mols do you want? That's M x L = 0.1M x 0.200L = 0.02 mols.
How many grams is that.
mols = grams/molar mass. You know molar mass and mols; solve for grams.
250 mL of 0.2 N. How many equivalents do you want? That's N x L = 0.05 equiv.
How many grams is that?
#equivalents = grams/equilvalent weight. You know # equivalents and equivalent weight; solve or grams.
100 mL 3% NaCl (I assume that is % w/w.)
3g NaCl/100 g solution.
The Na2CO3 is done the same way.
To calculate the mass and prepare the requested solutions, we need to know the molar mass of NaCl and Na2CO3. The molar mass of NaCl is approximately 58.44 g/mol, and the molar mass of Na2CO3 is approximately 105.99 g/mol.
1. Calculating the mass and preparing a 200 mL, 0.1 M NaCl solution:
- The molarity (M) of a solution is defined as the number of moles of solute per liter of solution.
- We need to calculate the number of moles of NaCl required for a 0.1 M solution using the equation:
moles = molarity × volume (in liters)
- Converting the volume from milliliters to liters:
volume = 200 mL ÷ 1000 = 0.2 L
- Calculating the number of moles:
moles = 0.1 mol/L × 0.2 L = 0.02 moles
- Finally, calculating the mass using the molar mass:
mass = moles × molar mass = 0.02 moles × 58.44 g/mol = 1.1688 g
- Therefore, to prepare a 200 mL, 0.1 M NaCl solution, you would need approximately 1.17 grams of NaCl.
2. Calculating the mass and preparing a 250 mL, 0.2 N Na2CO3 solution:
- Normality (N) is defined as the number of gram equivalents of solute per liter of solution.
- Since Na2CO3 is a diprotic base, its equivalent weight is half its molar mass.
- Calculating the equivalent weight of Na2CO3:
equivalent weight = molar mass / 2 = 105.99 g/mol / 2 = 52.995 g/equiv
- We need to calculate the grams of Na2CO3 required for a 0.2 N solution using the formula:
grams = normality × equivalent weight × volume (in liters)
- Converting the volume from milliliters to liters:
volume = 250 mL ÷ 1000 = 0.25 L
- Calculating the grams of Na2CO3:
grams = 0.2 N × 52.995 g/equiv × 0.25 L = 2.64975 g
- Therefore, to prepare a 250 mL, 0.2 N Na2CO3 solution, you would need approximately 2.65 grams of Na2CO3.
3. Calculating the mass and preparing a 100 mL, 3% NaCl solution:
- A 3% NaCl solution means that there are 3 grams of NaCl dissolved in 100 mL of solution.
- To calculate the mass, we can directly use the given percentage:
mass = percentage × volume (in grams)
mass = 3% × 100 mL = 3 g
- Therefore, to prepare a 100 mL, 3% NaCl solution, you would need 3 grams of NaCl.
To calculate the mass of NaCl and Na2CO3 needed to prepare the given solutions, you'll need to know the molar mass of each compound. The molar mass of NaCl (sodium chloride) is 58.44 g/mol, and the molar mass of Na2CO3 (sodium carbonate) is 105.99 g/mol.
Let's calculate each one separately:
1. To prepare a 200 ml 0.1 M NaCl solution:
The molarity (M) is given as 0.1 M, which means there are 0.1 moles of NaCl dissolved in 1 liter of solution. To calculate the number of moles needed for 200 ml (0.2L) of solution, you can use the following equation:
Moles of NaCl = Molarity (M) × Volume (L)
Moles of NaCl = 0.1 mol/L × 0.2 L = 0.02 moles
Now, to calculate the mass of NaCl using the moles, you can multiply the number of moles by the molar mass:
Mass of NaCl = Moles of NaCl × Molar mass of NaCl
Mass of NaCl = 0.02 moles × 58.44 g/mol = 1.1688 grams
2. To prepare a 250 ml 0.2 N Na2CO3 solution:
The normality (N) is given as 0.2 N, which means there are 0.2 equivalents of Na2CO3 dissolved in 1 liter of solution. To calculate the number of equivalents needed for 250 ml (0.25 L) of solution, you can use the following equation:
Equivalents of Na2CO3 = Normality (N) × Volume (L)
Equivalents of Na2CO3 = 0.2 Eq/L × 0.25 L = 0.05 equivalents
The molar mass of Na2CO3 is used to calculate the mass of Na2CO3 using the equivalents:
Mass of Na2CO3 = Equivalents of Na2CO3 × Molar mass of Na2CO3
Mass of Na2CO3 = 0.05 equivalents × 105.99 g/mol = 5.2995 grams
3. To prepare a 100 ml 3% NaCl solution:
A 3% solution means there are 3 grams of NaCl dissolved in 100 grams of solution. To determine the mass of NaCl needed to prepare a 100 ml (0.1L) solution, you can use the following equation:
Mass of NaCl = Percentage × Mass of solution
Mass of NaCl = 3% × 0.1 kg = 0.003 kg = 3 grams
So, you'll need 1.1688 grams of NaCl for the 0.1 M NaCl solution, 5.2995 grams of Na2CO3 for the 0.2 N Na2CO3 solution, and 3 grams of NaCl for the 3% NaCl solution.