Answer:
18.65004 grams H2O
Explanation:
First, we need to write down the balanced chemical equation for the decomposition reaction:
2LiOH -> H2O + Li2O
Since we have grams of LiOH and we need to know the grams of water, we need to convert to moles since we can only compare moles to moles.
The amu of LiOH is 23.947.
The given grams of LiOH is 63.. To convert to moles, we will divide 63 by 23.947..
This gives us 2.6310 moles LiOH..
To convert to moles of H2O (and later grams of H2O), we will use the mole fractions from the balanced equation...
When we look at the balanced equation we can see that 2 moles of LIOH can produce 1 mol of Water, so:
2.6310 moles 
= 1.3155 moles H2O
Now we will convert from moles to grams (we must multiply by the amu)
1.3155 moles H2O = 18.65 grams H2O
5 Na molecules and 5 Cl molecules
For the chemical reactiom to be at equilibrium:
1- The rate of forward reaction must be equal to the rate of the reverse reaction.
2- The mass of EACH element must be equal before and after the reaction (no NET change in mass), otherwise the equilibrium will shift.
Important note: you need to check the mass of each element before and after the reaction (i.e, reactants side and products side) and the not the mass of the system as a whole. This is because the mass of the whole system will be preserved whether the system is at equilibrium or not (this is the fundamental law of mass conservation)
Answer:
1.35 m
Explanation:
We can solve this problem by using the <em>freezing point depression formula</em>:
Where:
- ΔT is the temperature difference between the freezing point of the pure solvent (water) and the solution. In this case it is (<em>0 °C - -2.5 °C = 2.5 °C</em>).
- Kf is the cryoscopic constant, <em>for water it is 1.853 °C*kg/mol.</em>
- i is the van't Hoff factor, <em>as sugar does not dissociate in water, it has a value of 1</em>.
We <u>input the data</u>:
- 2.5 °C = 1.853 °C*kg/mol * m * 1
And <u>solve for m</u>:
