A 116.9 g sample of nitric acid solution that is 70.0% HNO3 contains how many moles of HNO3?
how did you get the answer
The sample has a mass of 116.9g. If it is 70% HNO3 (by mass but the post doesn't say that), then the mass of HNO3 is that 116.9 g is 116.9*0.70 = ? grams HNO3.
Then moles HNO3 = grams HNO3/molar mass HNO3.
To calculate the number of moles of HNO3 in a given sample, you need to use the concept of percent composition and the molar mass of HNO3.
Step 1: Determine the mass of HNO3 in the given sample.
First, convert the percentage to a decimal by dividing it by 100:
70.0% = 70.0/100 = 0.70
Then, multiply the decimal by the total mass of the solution to find the mass of HNO3:
Mass of HNO3 = 0.70 * 116.9 g = 81.83 g
Step 2: Calculate the number of moles using the molar mass of HNO3.
The molar mass of HNO3 is the sum of the atomic masses of its constituents:
H = 1.01 g/mol
N = 14.01 g/mol
O = 16.00 g/mol
Molar mass of HNO3 = (1.01 * 1) + (14.01 * 1) + (16.00 * 3) = 63.02 g/mol
Finally, divide the mass of HNO3 by the molar mass to obtain the number of moles:
Moles of HNO3 = 81.83 g / 63.02 g/mol = 1.298 mol
Therefore, the sample of nitric acid solution contains approximately 1.298 moles of HNO3.
I calculated this answer by using the formula:
moles = mass / molar mass
To calculate the number of moles of HNO3 in the given sample, we can use the formula:
Moles = Mass / molar mass
First, let's calculate the mass of HNO3 in the sample using the percentage composition. The sample is 70.0% HNO3, which means that 70.0% of the total mass is due to HNO3.
Mass of HNO3 = Percentage composition * Total mass
Mass of HNO3 = 70.0% * 116.9 g
Mass of HNO3 = 0.70 * 116.9 g
Mass of HNO3 = 81.83 g
Next, we need to find the molar mass of HNO3, which is the sum of the atomic masses of each element in the compound. The atomic masses of hydrogen (H), nitrogen (N), and oxygen (O) are approximately 1.01 g/mol, 14.01 g/mol, and 16.00 g/mol, respectively.
Molar mass of HNO3 = (1 * H) + (1 * N) + (3 * O)
Molar mass of HNO3 = (1 * 1.01 g/mol) + (1 * 14.01 g/mol) + (3 * 16.00 g/mol)
Molar mass of HNO3 = 1.01 g/mol + 14.01 g/mol + 48.00 g/mol
Molar mass of HNO3 = 63.02 g/mol
Finally, we can calculate the number of moles of HNO3 using the formula mentioned above:
Moles = Mass / molar mass
Moles = 81.83 g / 63.02 g/mol
Moles ≈ 1.298 mol
Therefore, the 116.9 g sample of nitric acid solution that is 70.0% HNO3 contains approximately 1.298 moles of HNO3.