A chemical bond between atoms with similar electronegatives
1 answer:
You might be interested in
Answer:
Explanation:
To find the density of nitrogen gas at STP which is standard temperature and pressure, certain parameters must be known.
The mass of the gas must be given or its volume.
Density of a substance is the mass per unit area;
Volume of gas at STP = number of moles x 22.4
Using the volume obtained here,
Density =
Then we can find the density.
The mass is very important.
Answer:
(B) 3
Explanation:
Citric acid has an acid dissociation constant (Ka) of 8.4 × 10⁻⁴. When it forms a buffer with its conjugate base (citrate), we can calculate the pH using the Henderson-Hasselbalch's equation.
The optimum range of pH is pKa ± 1. The pKa is -log Ka = -log (8.4 × 10⁻⁴) = 3.1. The buffer would be more effective for pH between 2.1 and 4.1, especially around 3.1. So the best choice is (B) 3.