Answer:
She can add 380 g of salt to 1 L of hot water (75 °C) and stir until all the salt dissolves. Then, she can carefully cool the solution to room temperature.
Explanation:
A supersaturated solution contains more salt than it can normally hold at a given temperature.
A saturated solution at 25 °C contains 360 g of salt per litre, and water at 70 °C can hold more salt.
Yasmin can dissolve 380 g of salt in 1 L of water at 70 °C. Then she can carefully cool the solution to 25 °C, and she will have a supersaturated solution.
B and D are wrong. The most salt that will dissolve at 25 °C is 360 g. She will have a saturated solution.
C is wrong. Only 356 g of salt will dissolve at 5 °C, so that's what Yasmin will have in her solution at 25 °C. She will have a dilute solution.
1. Change in color
2. Formation of bubbles
3. Formation of a precipitate
4. Begins to make an odor
The chemical reaction would be:
<span>CuSO4(aq) + NaOH(aq) = Cu(OH)2(s) + Na2SO4(aq)
One observation would be the formation of a precipitate since one of the products is not readily soluble to aqueous solution. A formation of a blue precipitate will be observed.</span>
24= y2k* - 2x H202 grams in mass
Answer: b. accepts ions from acids
Explanation:
According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions when dissolved in water and an acid is defined as a substance which donates hydronium ions in water.
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates ions and a base is defined as a substance which accepts ions.
Here water is donating ions, and thus act as acid and ammoia is accepting ions from water and thus is a base.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
Thus base is a substance which accepts ions from acids.