Answer: 
.
Explanation:
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
(1)
(2)
The final reaction is:
(3)
By adding (1) and (2)
Hence .
0.025 g
Sig Fig applies only to numbers that not zero, only except when the zero is after the the number.
For example:
0.0255 is three sigfigs
0.0050 is two sig figs
0.0005 is one sigfig
Answer:
Do you have the video so I can watch it?
Explanation:
During this reaction, carbon dioxide<span> and water are converted into </span>glucose<span> and</span>oxygen<span>. The reaction requires light energy, which is absorbed by a green substance called </span>chlorophyll. Photosynthesis takes place in leaf cells. These containchloroplasts<span>, which are tiny objects containing </span>chlorophyll<span>.</span>
1) The saturation point at 25°C is 35.7 g of NaCl / 100 g of water => 35.7 %
Under normal circumstances water will not accept more salt than that.
2) The solution with 1.55 mol of NaCl dissolved in 250 mL of water =>
molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol
grams of NaCl = 1.55 mol * (molar mass of NaCl) = 1.55mol * 58.44 g/mol = 90.58 grams of NaCl
grams of water = 250 mL * 1 g/mL = 250 g/g.
Concentration of the solution: [90.58 g NaCl / 250 g H2O] * 100 = 36.23 %
3) Conclusion: the solution has more salt than the saturation value. This means that the solution is supersaturated.
Supersaturation is a special condition, which is unstable, but that is not part of the questions.
The answer is supersaturated,
