A chemist dissolves 699. mg of pure hydrobromic acid in enough water to make up 180. mL of solution. Calculate the pH of the sol
ution. Be sure your answer has the correct number of significant digits.
1 answer:
Answer: 1.32
Explanation:
First, we must obtain the molar mass of HBr. After that, we try to obtain the concentration of the hydrobromic acid from the formula n=CV since the volume of solution and mass of acid was provided. Recall that n=m/M. If the concentration of acid is thus obtained, we make use of the fact that the concentration of H+ in the acid is equal to the molar concentration of HBr to obtain the pH. The pH is the negative logarithm of the concentration we obtained in the initial step.
You might be interested in
<u>Answer:</u> The amount of kilocalories contained in the given serving of crackes is 0.120 kCal
<u>Explanation:</u>
<u>As per the USDA:</u>
Carbohydrates provide 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram
We are given:
Mass of fat in the crackers = 4 g
Mass of carbohydrates in the crackers = 19 g
Mass of protein in the crackers = 2 g
Conversion factor used: 1 kCal = 1000 Cal
Applying unitary method:
- <u>For Fat:</u>
1 gram of fat provides 9 calories
So, 4 gram of fat will provide =
- <u>For Carbohydrates:</u>
1 gram of carbohydrates provides 4 calories
So, 19 gram of carbohydrates will provide =
- <u>For Proteins:</u>
1 gram of proteins provides 4 calories
So, 2 gram of fat will provide =
Total kilocalories per serving = [0.036 + 0.076 + 0.008] kCal = 0.120 kCal
Hence, the amount of kilocalories contained in the given serving of crackes is 0.120 kCal