if 16.o ml HCL is needed to neutralize from a 2.25g sample of organic material, calculate the mass percentage of N in the sample
You need to know the concn of the HCl.
To calculate the mass percentage of nitrogen (N) in the sample, we need to determine the amount of nitrogen present in the organic material. Here's how you can do it step-by-step:
Step 1: Calculate the number of moles of HCl used in the neutralization reaction.
We are given that 16.0 mL of HCl is needed to neutralize the sample. However, we need this value in moles. To convert from volume (mL) to moles, we need to use the molarity of the HCl solution.
Assuming the molarity of HCl is 1 M (you may need to adjust this if given a different concentration), we can use the following formula:
moles of HCl = volume (in L) x molarity
16.0 mL = 0.016 L (divide by 1000 to convert mL to L)
moles of HCl = 0.016 L x 1 M = 0.016 moles HCl
Step 2: Determine the molar ratio between HCl and nitrogen (N).
From the balanced chemical equation representing the neutralization reaction, we can determine the molar ratio between HCl and nitrogen (N).
Since we are given that the HCl completely neutralizes the sample, the molar ratios between HCl and nitrogen (N) are 1:1. This means that one mole of HCl reacts with one mole of nitrogen.
Step 3: Calculate the number of moles of nitrogen (N) in the sample.
Since the molar ratio between HCl and nitrogen (N) is 1:1, the number of moles of nitrogen (N) is also 0.016 moles.
Step 4: Calculate the mass of nitrogen (N) in the sample.
To calculate the mass of nitrogen (N) in the sample, we need to convert the number of moles of nitrogen to grams.
To do this, we will use the molar mass of nitrogen. The molar mass of nitrogen (N) is approximately 14.01 g/mol.
mass of N = moles of N x molar mass of N
mass of N = 0.016 moles x 14.01 g/mol ≈ 0.22416 g
Step 5: Calculate the mass percentage of nitrogen (N) in the sample.
Finally, we can calculate the mass percentage of nitrogen (N) in the sample by dividing the mass of nitrogen by the mass of the entire sample (2.25 g) and multiplying by 100%.
mass percentage of N = (mass of N / mass of sample) x 100%
mass percentage of N = (0.22416 g / 2.25 g) x 100% ≈ 9.96%
Therefore, the mass percentage of nitrogen (N) in the sample is approximately 9.96%.