How many moles of ammonium ions are in 8.794g of ammonium carbonate?
I got .1832 as an answer and I was told that I was very close and I just may have done some kind sigfig or calculation error but I have no idea what it is since I did this problem so many times only to get the same answer.
When you post a question like this it keeps us in the dark. In addition to the problem you should have posted you work. That way we could find the error.
What are you using for the molar mass of (NH4)2CO3? I have it as 96.086.
8.794/96.086 = 0.09152
mols NH4^+ is twice that so
0.09152*2 = 0.18304 which I would round to 0.1830.
Yeah it was that last digit that threw me off. Thanks for the help. I rounded early so the calculation came out different.
Thanks
To determine the number of moles of ammonium ions in a given mass of ammonium carbonate, you need to follow these steps:
Step 1: Find the molar mass of ammonium carbonate.
The molar mass of ammonium carbonate (NH4)2CO3 can be calculated by summing up the atomic masses of each element in the compound.
NH4: (1 x 14.01 g/mol) + (4 x 1.01 g/mol) = 18.05 g/mol
CO3: (1 x 12.01 g/mol) + (3 x 16.00 g/mol) = 60.01 g/mol
Therefore, the molar mass of ammonium carbonate (NH4)2CO3 is:
2 x 18.05 g/mol + 60.01 g/mol = 96.11 g/mol.
Step 2: Calculate the number of moles.
To find the number of moles, divide the given mass of ammonium carbonate by its molar mass.
Moles = Mass / Molar mass
Moles = 8.794 g / 96.11 g/mol
Moles ≈ 0.0913 mol (rounded to four significant figures).
Step 3: Determine the number of moles of ammonium ions.
In ammonium carbonate, (NH4)2CO3, there are 2 moles of ammonium ions (NH4) per 1 mole of ammonium carbonate (NH4)2CO3. Therefore, multiply the number of moles of ammonium carbonate by 2 to get the number of moles of ammonium ions.
Moles of ammonium ions = 0.0913 mol x 2
Moles of ammonium ions ≈ 0.183 mol (rounded to three significant figures).
The answer is approximately 0.183 moles of ammonium ions. However, please note that the given question states that your answer of 0.1832 is very close, so it could indeed be a significant figures or calculation error. Double-check your calculations and make sure you are rounding to the correct number of significant figures.