The first thing you need to do with problem of this kind is to write the chemical equation. This would help you in calculations later. First, convert how many moles are there in 1.75g of carbon dioxide. Then, from the chemical equation you will know how many moles of sodium bicarbonate formed with 1 mole of carbon dioxide. Then convert the moles of sodium bicarbonate to grams using the molecular weight of the compound. You now have your answer.
Answer:
The ice will not melt, and the temperature will remain at 0°C.
Explanation:
The reaction of the sodium in water is exothermic because heat is being released. In an isolated system, the change in heat must be 0, so the released heat must be absorbed by the ice.
The molar mass of Na is 23 g/mol, so the number of moles that reacted was:
n = 0.250 g/ 23g/mol
n = 0.011 mol
By the reaction:
2 moles ------- -368 kJ
0.011 mol ----- x
By a simple direct three rule:
2x = -4.048
x = -2.024 kJ/mol
So the ice will absorbs 2.024 kJ/mol, which is less than the necessary to melt it (6.02 kJ/mol). Then, the ice will not melt.
The temperature of a pure substance didn't change until all of it has changed of phase, so the temperature must remain at 0°C.
Answer:
Law of definite proportions, statement that every chemical compound contains fixed and constant proportions (by mass) of its constituent elements.
