Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem.
For the purpose we have to know following equation for freezing
point depression:
ΔTf=Kf*b
and that Kf of water is 1.86°C/m.
From the formula we can determine molality (b):
b=Δtf/Kf=0.77/1.86= 0.414 mole/kg
Now when we know molality, we can calculate mass of sucrose
in solution:
b=n/m(H20) => n(sucrose)=b*m(H20) = 0.414 mole/kg *0.1 kg = 0.0414 mole
Finally, we can determine the molar mass of sucrose:
M=m/n=14.2/0.0414= 343g/mole
This is a combustion reaction, which always has the hydrocarbon and oxygen as reactants and then carbon dioxide and water (which is steam in this case) as products.
C8H18 + O2 —> CO2 + H2O
Balance your carbons first. You want to get 8 carbons on both sides.
C8H18 + O2 —> 8CO2 + H2O
Now balance your hydrogens. You want 18 hydrogens on both sides.
C8H18 + O2 —> 8CO2 + 9H2O
Now balance your oxygens. You have 2 on the left and 25 on the right. The O2 reactant needs a coefficient of 12.5 to balance this.
C8H18 + 12.5O2 —> 8CO2 + 9H2O
However, you can’t have decimals for coefficients in a reaction. So, multiply everything by 2.
2C8H18 + 25O2 —> 16CO2 + 18H2O
Now, use your mole ratio of 18 mol H2O for every 2 mol C8H18 to solve.
5.74 mol C8H18 • (18 mol H2O / 2 mol C8H18) = 51.7 mol H2O (steam)
To make a stable ionic compound you need 8 valence electrons and since nitrogen has 5 valence electrons he would need 4 more ions of Elements to make a full 8,
