<h3>
<u>Answer:</u></h3>
<u>1 mole of a gas at STP occupies 22.4 L volume </u>
<u>Now the volume is given =78.4 therefore,</u>
<u>No. of moles of gas = 78.4 ÷ 22.4 = 3.5 moles</u>
<u>I hope it helps you~</u>
Answer:
When the two gases are mixed, the ammonium chloride precipitates in the tube walls.
Explanation:
This is the reaction:
HCl (g) + NH₃(g) → NH₄Cl (s) ↓
As the product formed is solid at room temperature, a suspension is first formed in the internal air of the tube that appears as a cloud. Afterwards it finally precipitates into the walls forming a white layer
Answer: It showed that all atoms contain electrons.
Explanation:
- J.J. Thomson's experiments inside a cathode ray tube in the presence of an electric field showed that all atoms contain tiny negatively charged subatomic particles "electrons".
- Also, Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup."
- Furthermore, Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny positively-charged nucleus.
- Then, Rutherford proposed the nuclear model of the atom based on these results.
Answer:
a) pH = 4.68 (more effective)
b) pH =4.44.
Explanation:
The pH of buffer solution is obtained by Henderson Hassalbalch's equation.
The equation is:
![pH =pKa +log\frac{[salt]}{[acid]}](https://tex.z-dn.net/?f=pH%20%3DpKa%20%2Blog%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D)
a) pKa of acetic acid = 4.74
[salt] = [CH₃COONa] = 1.4 M
[acid] = [CH₃COOH] = 1.6 M

This is more effective as there is very less difference in the concentration of salt and acid.
b) pKa of acetic acid = 4.74
[salt] = [CH₃COONa] = 0.1 M
[acid] = [CH₃COOH] = 0.2 M

Answer:
a. Are miscible because each can hydrogen bond with the other.
Explanation:
Both ethanol and water are miscible. The reason why they can both mix freely is due to the hydrogen bonds that will form between their molecular structure.
Hydrogen bonds are special dipole-dipole attraction between polar molecules in which hydrogen atoms are directly joined to an electronegative atom.
Ethanol has an hydroxyl group which will bond to form an intermolecular bond with the oxygen and hydrogen on the water molecule. This attraction makes them miscible.