Answer:-
Water is highly ordered. In water each oxygen atom is connected to others around it through hydrogen bonding via bridging hydrogen atoms. When a salt like NaCl is dissolved, some of these Hydrogen bonds break.
When a salt like NaCl dissolves in water, the NaCl breaks in to ions Na+ and Cl-.
The water molecules now surround these ions.
The slightly negative oxygen end of water molecule gets near the Na+, while the slightly positive Hydrogen of water molecule gets near the Cl-.
So before salt sample dissolve, the water molecules were highly ordered due to hydrogen bonding. Now after salt dissolve there is a decrease in order and thus an increase in disorder of the water molecules.
Due to increase in disorder, entropy which is a measure of disorder increases. Since entropy increases, delta S for the process is positive.
Models in science help you get the idea of what something looks like that's why your teacher may ask you to draw a diagram to help you remember what the object looks like.
Hope this helps.
Answer:
yes the one that is circled is correct
Explanation:
The answer is dissolved in water, because in chemistry, (aq) is shorthand for aqueous solution.
Answer:
Explanation:
<u>1) Chemical equation (given)</u>
<u>2) Theoretical yield</u>
<u>a) Convert mass of NaHCO₃ to moles:</u>
- n = mass in grams / molar mass
- molar mass = 84.007 g/mol
- n = 2.36 g / 84.007 g/mol = 0.02809 mol
<u>b) Mole ratio:</u>
- 2 mol NaHCO₃ : 1 mol H₂CO₃
<u>c) Proportionality:</u>
- 2 mol NaHCO₃ / mol H₂CO₃ = 0.02809 mol NaHCO₃ / x
⇒ x = 0.2809 / 2 mol H₂CO₃ = 0.01405 mol H₂CO₃
<u>3) Actual yield</u>
<u>a) Mass balance</u>: 2.36 g - 1.57 g = 0.79 g
<u>b) Convert 0.79 g of carbonic acid to number of moles</u>:
- n = mass in grams / molar mass
- n = 0.79 g / 62.03 g/mol = 0.01274 mol
<u>4) Percentage yield, y (%)</u>
- y (%) = actual yield / theoretical yield × 100
- y (%) = 0.1274 mol / 0.1405 mol × 100 = 90.68%
The answer must show 3 significant figures, so y(%) = 90.7%.
