Answer:
The molality of the KCl solution is 11.8 molal
Explanation:
Step 1: Data given
Mol fracrion KCl = 0.175
Molar mass KCl = 74.55 g/mol
Molar mass H2O = 18.02 g/mol
Step 2: Calculate mol fraction H2O
mol fraction H2O = 1 - 0.175 = 0.825
Step 3: Calulate mass of H2O
Suppose the total moles = 1.0 mol
Mass H2O = moles H2O * molar mass
Mass H2O = 0.825 * 18.02 g/mol
Mass H2O = 14.87 grams = 0.01487 kg
Step 4: Calculate molality
Molality KCl = 0.175 / 0.01487 kg
Molality KCl = 11.8 molal
The molality of the KCl solution is 11.8 molal
1. the amount of heat that it would take would be :
5.1 x 10^4 J
2. I think the substance would be : Iron
3. the amount of heat required would be :
1.13 x 10^4 kJ
Hope this helps
Answer:
The empirical formula = molecular formula = C13H18O2
Explanation:
in 100% compound we have 75.6 % Carbon ( Molar mass = 12g/mole), 8.80% hydrogen ( Molar mass = 1.01 g/mole) and 15.5% Oxygen (Molar mass = 16.01 g/mole).
Carbon: 75.6g / 12 = 6.29
Hydrogen: 8.80/ 1 = 8.80
Oxygen: 15.5/ 16 = 0.97
⇒0.97 is the smallest so we divide everything through by 0.97
C: 6.29 / 0.97 = 6.48 ≈ 6.5
H: 8.80 /0.97 = 9
O: 0.97 / 0.97 = 1
To get rid of decimals, we multiply by 2
C: 6.5 x 2 = 13
H: 9 x 2 = 18
O: 1 x 2 = 2
The empirical formula = C13H18O2
13x 12g/mol + 18x1g/mol + 2x 16g/mol = 156 + 18 + 32 = 206g/mol which is the molar mass of ibuprofen
The empirical formula = molecular formula = C13H18O2
