Answer:
2.2 °C/m
Explanation:
It seems the question is incomplete. However, this problem has been found in a web search, with values as follow:
" A certain substance X melts at a temperature of -9.9 °C. But if a 350 g sample of X is prepared with 31.8 g of urea (CH₄N₂O) dissolved in it, the sample is found to have a melting point of -13.2°C instead. Calculate the molal freezing point depression constant of X. Round your answer to 2 significant digits. "
So we use the formula for <em>freezing point depression</em>:
In this case, ΔTf = 13.2 - 9.9 = 3.3°C
m is the molality (moles solute/kg solvent)
- 350 g X ⇒ 350/1000 = 0.35 kg X
- 31.8 g Urea ÷ 60 g/mol = 0.53 mol Urea
Molality = 0.53 / 0.35 = 1.51 m
So now we have all the required data to <u>solve for Kf</u>:
Answer:
When popcorn is popped, liquid inside the kernel is changed to steam. Pressure from the steam builds up inside the kernel. When the pressure reached a critical stage the kernel pops turning itself inside out. This is a physical change.
Explanation:
Answer:
6.00%
Explanation:
Step 1: Given data
Accepted value for the number of calories in a Bananas Foster: 300 calories
Measured value for the number of calories in a Bananas Foster: 318 calories
Step 2: Calculate the percent error in the measure
We will use the following expression.
%error = |accepted value - experimental value|/ accepted value × 100%
%error = |300 cal - 318 cal|/ 300 cal × 100% = 6.00%
Answer:
The correct option is C.
Explanation:
Carbohydrates are one of the macro molecules that are consumed by living organisms. The end product of carbohydrate is glucose. Glucose is a very important fuel that the body cells used to produce energy, which they use to carry out their daily activities. Glucose is also known as blood sugar and it is the only fuel that living cells can use for the production of ATP. Other food macro molecules such as lipids and proteins can also be converted to glucose if there is a need for that. Glucose is always stored in the body in form of glycogen.
The statement given in option C about glucose is wrong because glucose is a monosaccharide and not a disaccharide.
