Answer:
b) add 130 g of NaCH₃CO₂ to 100 mL of H₂O at 80 °C while stirring until all the solid dissolves, then let the solution cool to room temperature.
Explanation:
The solubility of NaCH₃CO₂ in water is ~1.23 g/mL. This means that at room temperature, we can dissolve 1.23 g of solute in 1 mL of water (solvent).
<em>What would be the best method for preparing a supersaturated NaCH₃CO₂ solution?</em>
<em>a) add 130 g of NaCH₃CO₂ to 100 mL of H₂O at room temperature while stirring until all the solid dissolves.</em> NO. At room temperature, in 100 mL of H₂O can only be dissolved 123 g of solute. If we add 130 g of solute, 123 g will dissolve and the rest (7 g) will precipitate. The resulting solution will be saturated.
<em>b) add 130 g of NaCH₃CO₂ to 100 mL of H₂O at 80 °C while stirring until all the solid dissolves, then let the solution cool to room temperature. </em>YES. The solubility of NaCH₃CO₂ at 80 °C is ~1.50g/mL. If we add 130 g of solute at 80 °C and let it slowly cool (and without any perturbation), the resulting solution at room temperature will be supersaturated.
<em>c) add 1.23 g of NaCH₃CO₂ to 200 mL of H₂O at 80 °C while stirring until all the solid dissolves, then let the solution cool to room temperature.</em> NO. If we add 1.23 g of solute to 200 mL of water, the resulting solution will have a concentration of 1.23 g/200 mL = 0.00615 g/mL, which represents an unsaturated solution.
Since hydrogen bonding is a stronger intermolecular force than van der Waals forces, more energy is required to separate the molecules of ethanol than the molecules of ethane. Thus ethanol has a higher melting point than ethane.
1×10^-4 = 0,0001M
pH = -log[H+]
pH = -log0,0001
pH = 4
Answer:
- <u><em>The leftover reactant is the nitrogen gas, N₂.</em></u>
Explanation:
As per your description:
<u>1. Square on the left: N₂(g)</u>
- 3 units of two joint circles: this represents 3 molecules of nitrogen gas, N₂(g).
<u>2. Square on the right: H₂(g)</u>
- 3 units of two joint circles: this represents 3 molecules of hydrogen gas, H₂(g).
<u>3. Reaction</u>
If the maximum possible amount of NH₃ is formed during the reaction, you assume that the reaction goes to completion.
The chemical equation that represents the reaction is:
Which must be balanced:
That means that 1 molecule (or 1 mol) of N₂(g) reacts with 3 molecules (or 3 moles ) of H₂(g) to produce 2 molecules (or 2 moles) of NH₃(g).
Since, the squares show that there are 3 molecules of each reactant, the 3 molecules of hydrogen gas will be able to react with 1 molecule of nitrogen gas. When that happens, all the hydrogen gas is consumend and yet two molecules of nitrogen gas will remain unreacted. Hence, the nitrogen gas is the leftover reactant.
<em>grou</em><em>p</em><em> </em><em>4</em><em> </em><em>,</em><em> period</em><em> </em><em>4</em>
Explanation:
from the electron configuration,
the element is Titanium
and it's has 22 electrons on it's shells , so wen you place it on the periodic table, you will see that it's in group 4 period 4
