Answer:
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
Explanation:
A buffer system is formed in 1 of 2 ways:
- A weak acid and its conjugate base.
- A weak base and its conjugate acid.
Determine whether mixing each pair of the following results in a buffer.
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
YES. NH₃ is a weak base and NH₄⁺ (from NH₄Cl ) is its conjugate base.
b. 50.0 mL of 0.10 M HCl with 35.0 mL of 0.150 M NaOH.
NO. HCl is a strong acid and NaOH is a strong base.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
YES. HF is a weak acid and it reacts with NaOH to form NaF, which contains F⁻ (its conjugate base).
d. 175.0 mL of 0.10 M NH₃ with 150.0 mL of 0.12 M NaOH.
NO. Both are bases.
The answer to your question about the scientific method is Make an observation.
Ask a question.
Form a hypothesis, or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or predictions.
A compound was found to be soluble in water. It was also found that addition of acid to an aqueous solution of this compound resulted in the formation of carbon dioxide. Which one of the following cations would form a precipitate when added to an aqueous solution of this compound?
Options
a. NH4
b. K
c. Cr
d. Rb
e. Na
Answer: c: Cr
Explanation:
The aforementioned reaction are banters for to distract ones focus from the question.
However it should be noted that
Cr can be found in tannery waste water showing that it can be soluble in water.
The carbonate compound when reacting with acid CO_2 evolves.
Focusing on the cation that would form a precipitate when added to an aqueous solution.
Chemical precipitation method is a common method for to remove chromium and to recover it from tannery wastewater.
Cr would form a precipitate.
Answer:
Explanation:
Given that,
Area of sheet of Aluminium foil is 1 m²
Mass of the sheet = 3.636 g
The density of Aluminium, 
We need to find the thickness of the sheet in millimeters.
The density of an object is given in terms of its mass and volume as follows :
V = volume, V = A×t, t = thickness of the sheet
So,
Since, 1 cm = 10 mm
So,
t = 0.00134 mm
or
