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:
The nuclear decay of radioactive elements is a process that is a useful tool for determining the absolute age of fossils and rocks. It is used as a clock, in which daughter elements or isotopes converted from parent isotopes by decaying at a particular time.
Radioactive decay rates are constant and do not change over time. It is measured in half-life. A half-life is a time it takes half of a parent isotope to decay and converted into a stable daughter isotope. How many parent isotopes and daughter isotopes present in the fossil or their abundance can help in determining the age of fossil or rock.
i mean technically, no. only because water is water and water makes things wet. you know? unless you pour water onto water then idk honestly, truly...
Answer:
Engineering is all about solving problems using math, science, and technical knowledge. And engineers have solved a lot of problems in the world by designing and building various technologies. We have everything from machines that can breathe for you in hospitals to suspension bridges to computers we use every day. All of these things were once designed by engineers using the engineering design process.
Explanation:
A physical change is when something don't permanently change
