Ok to answer this question we firsst need to fin the number of mol of Urea (CH4N2O). to do this we simply :
1 mol of urea =15/60.055 = 0.25mol
therefore 200g of water contain 0.25mol
the next step is to determine the malality of our solution in 200g of water, to do this we say:
200 g = 1Kg/1000g = 0.2kg
therefor 0.25mol/0.2Kg = 1.25mol/kg
and from the equation:
we know that i = 1
we are given Kf
b is the molality that we just calculated
therefore;
the solutions freezing point is -2.325°C
Answer: decomposition
Explanation:
1 . Combustion is a type of chemical reaction in which a hydrocarbon reacts with oxygen to form carbon dioxide ans water along with liberation of large amount of energy.
2. Decomposition is a type of chemical reaction in which a single reactant gives two or more than two products.

3. Single replacement is a type of chemical reaction in which a more reactive element displaces the less reactive element from its slat solution.
4. Synthesis is a type of chemical reaction in which two or more than two reactants combine together to give a single product.
Answer:
a) 25%
b) 27.5 g
c) 90%
Explanation:
a) 75% fat-free by weight means 25% of the weight is made by fat.
b) 110 g ___ 100%
x ___ 25%
x = 27.5g
Each hot dog has 27.5g of fat.
c) 9 cal ___ 1 g fat
y ___ 27.5 g fat
y = 247.5 cal
275 cal ___ 100%
247.5 cal ___ z
z = 90%
90 % of the calories come from fat.
To solve the problem, we assume the sample to be ideal. Then, we use the ideal gas equation which is expressed as PV = nRT. From the first condition of the nitrogen gas sample, we calculate the number of moles.
n = PV / RT
n = (98.7x 10^3 Pa x 0.01 m^3) / (8.314 Pa m^3/ mol K) x 298.15 K
n = 0.40 mol N2
At the second condition, the number of moles stays the same however pressure and temperature was changed. So, the new volume is calculated as follows:
V = nRT / P
V = 0.40 x 8.314 x 293.15 / 102.7 x 10^3
V = 9.49 x 10^-3 m^3 or 9.49 L