Answer:
0.278 mol
Explanation:
Step 1: Given and required data
Mass of acetic acid (m): 16.7 g
Chemical formula of acetic acid: CH₃COOH (C₂H₄O₂)
Step 2: Calculate the molar mass (M) of acetic acid
We will use the following expression.
M(C₂H₄O₂) = 2 × M(C) + 4 × M(H) + 2 × M(O)
M(C₂H₄O₂) = 2 × 12.01 g/mol + 4 × 1.01 g/mol + 2 × 16.00 g/mol = 60.06 g/mol
Step 3: Calculate the number of moles (n) of acetic acid
We will use the following expression.
n = m/M
n = 16.7 g/(60.06 g/mol) = 0.278 mol
Answer : Hydrogen fuel cells are considered to be better than fossil fuels because of many reasons, some of them are mentioned below;
a) It is a clean fuel it does not causes any pollution to the atmosphere.
b) It more efficient than many other available fuel cells.
c) Preparation of hydrogen fuel cell relies on the free or compounded state availability hydrogen in nature, which in plenty.
d) They do not make any noise while it is being used. Hence these are considered to be quiet fuel cell.
e) They can be used for longer hours as compared to other fuel cells.
The answer to the question being asked as to who discovered and developed a model of an atom that looked like a nucleus surrounded by an electron is no other than Ernest Rutherford. Ernest Rutherford successful discovered the model by contradicting the idea of JJ Thomson.
The question is incomplete, the complete question is;
2. How many moles of NaOH are there in a 20.0mL sample of an 0.101M solution?
3. How many grams of benzoic acid would be required to react with the NaOH
sample mention in Question 2?
Answer:
0.247 g
Explanation:
Recall that;
n =CV
n = number of moles
C = concentration
V = volume (in litres)
So;
n = 0.101 * 20/1000
n = 2.02 * 10^-3 moles
The equation of the reaction is;
C6H5COOH(s)+NaOH(aq) ---------> C6H5COO-Na+ (aq)+H2O(l)
Given that the reaction is in 1:1 molar ratio
number of moles of benzoic acid required= 2.02 * 10^-3 moles * 122.12 g/mol = 0.247 g
Answer:
109.0
Explanation:
When adding or subtracting values, you must round your answer to the same "place" as the measurement with its last significant figure <em>furthest to the left</em>.
That is, you round off to the same number of decimal places as the measurement with the <em>fewest decimal places</em>.
43.<u>0
</u>
50.<u>0</u>
<u>+16.0
</u>
109.<u>0</u>
In each measurement, the “0” is the significant figure furthest to the left, so you round off the number to the “tenths" place. That's the last column that the measurements share.
109.0 → 109.0 (rounded to the “tenths” place)
In other words, you do not round off, and the sum has four significant figures.
